Twenty-Five Per Cent of Unknown: Tracing a Number This Trade Repeats

1. Introduction: the number behind the sales case

Two earlier articles in this journal stopped to note that a figure could not be traced. This one follows a figure all the way and reports what is at the end of it.

1.1 The trail ends nowhere

Which §4 establishes.

1.2 And the claim has a structural problem

It assigns a cause to the one category of fire defined by no cause having been assigned, which is §12.

2. Why this journal is doing this

Because it is the same exercise we have applied to everybody else.

Our article on the brown recluse traced a diagnosis to its evidence and found a specimen record. Our article on fertility control traced an efficacy claim to its evidence and found bait uptake. This is the trade's own economic case receiving the same treatment.

2.1 And because the trade's credibility runs on these figures

Our credence goods article established that a client cannot evaluate this service directly, so they evaluate the claims made about it. When those claims turn out to be untraceable, the whole apparatus of trust the trade depends on is the thing that erodes.

Which makes checking them a professional interest rather than a pedantic one.

2.2 And it is against our interest

Section 25 says how much.

3. The claim

In its several forms.

Twenty-five per cent, in one formulation.² Twenty to twenty-five per cent, in another.¹ And twenty percent (20%) of fires of undetermined origin, in a third.⁶

3.1 A round number in every version

Twenty, twenty-five, or the range between them. No source gives a figure with a decimal, a confidence interval or an odd digit.²¹

Which is what a figure derived from a calculation would usually carry, and its absence is a small signal on its own.

3.2 A five-point spread across three sources

Which for a figure of this kind is not large, and is enough to show that nobody is working from a single published value.

3.3 And the wording varies too

Unknown causes, undetermined origin, and mystery fires all appear, which are three descriptions of what may or may not be the same administrative category.

4. Where the sources say it comes from

Following each one upstream.

One pest control firm: according to the Illinois Department of Public Health, 25% of fires attributed to "unknown causes" are caused by rodents chewing electrical wires and gas lines.⁴

Another: based on a 2012 issue of Pest World, rodents and home fires may be related in some cases. Current estimates attribute that rodents are responsible for 20% to 25% of fires with unknown causes.³

4.1 Note the second firm's own hedge

That rodents and home fires may be related in some cases, which is a careful sentence placed immediately before the confident one that follows.³

The same paragraph contains both the qualified version and the quantified one, which suggests the writer knew the figure was soft and included it anyway.

4.2 So two firms cite two different authorities

A state health department and a trade association's magazine.⁴³

4.3 And neither authority cites anything

Which §§5 and 7 establish.

5. The trade association version

On the association's own commercial pest news page.

It's estimated that rodents are responsible for 20 percent to 25 percent of all fires of unknown causes because of their propensity for chewing electrical wiring and gas lines.¹

5.1 This is the association's own publication

Not a member firm's blog but the national body's commercial pest news channel, reproduced from a property management magazine.¹

Which makes it the closest thing the trade has to an authoritative statement of its own position, and is why we treat this source as the important one in the chain.

5.2 It's estimated

By whom is not stated.¹

6. Which cites precisely, once

And this is the detail that makes the omission conspicuous.

The same paragraph opens by quoting a named fire protection association: fire departments responded to 46,500 reported home structure fires involving electrical failure or malfunction in 2010. These fires resulted in 420 civilian deaths, 1,520 civilian injuries and $1.5 billion in direct property damage.¹

6.1 The bracketing is worth noticing

The attributed material is presented inside quotation marks and the unattributed claim is not, which is the ordinary typographic signal that one is somebody else's words and the other is the writer's.¹

So the convention was observed correctly and the effect in §6.3 happens anyway.

6.2 That is a proper citation

Named body, stated year, four specific figures, presented as a quotation.¹

6.3 And then the rodent share arrives unattributed

In the next sentence of the same paragraph.¹

6.4 The structure is worth naming

An attributed denominator and an unattributed numerator, placed adjacently, so that the authority of the first transfers to the second by proximity.

We are not alleging that anybody arranged it deliberately. We are describing the effect on a reader, and that observation is ours.

7. The government version

The one everybody points to.

On a state health department's municipal rodent management page: it is estimated that 25 percent of all fires attributed to "unknown causes" are probably started by rodents gnawing on gas lines, electrical wiring and matches.²

7.1 Also unattributed

It is estimated, with no indication by whom.²

7.2 And gas lines and matches are in the list

Which is a wider claim than wiring alone: three ignition routes rather than one.²

Downstream sources narrow it to wiring, or to wiring and gas lines, which is a change in the claim's content rather than only in its confidence. Nobody appears to have noticed the matches.

7.3 The page is otherwise substantive

It describes integrated pest management properly, notes that a typical large city annually receives more than 10,000 complaints about rodent problems, and sets out a sanitation-first control sequence that our own articles endorse.²

This is not a poor document. It contains one sentence that carries no source.

8. And the laundering step

Which is visible in a single quotation.

The pest control firm writes according to the Illinois Department of Public Health, and states the figure.⁴

8.1 The attribution is accurate

The department does say it. The firm has not misquoted anybody.²⁴

8.2 What has changed is the apparent status

An unsourced estimate on a government page becomes, one step downstream, a figure attributed to a government health department.

9. What that does

Our analysis of the mechanism.

A reader encountering according to a state health department reasonably infers that a health department established the figure. The phrase reports where the writer found it and is read as where it came from.

9.1 The two are different relations

Found in and established by, and citation conventions do not distinguish them in ordinary prose.

9.2 And the effect compounds

Once one firm has written according to a state health department, the next writer finds a claim that appears to have two independent supports: the department and the firm citing it. Neither added any evidence.

Which is how a single unsourced sentence acquires a literature, and that description is ours.

9.3 Which makes government pages load-bearing

Because anything stated on one acquires a citability that an identical sentence on a company blog does not have.

That is our argument and it is why §7.2 insists the page is otherwise good.

10. The hedges

What happens to the qualifiers as the claim travels.

The health department: it is estimated that a quarter are probably started by rodents.²

The trade association: it's estimated that rodents are responsible for twenty to twenty-five per cent.¹

A pest control firm: approximately 25% of house fires attributed to 'unknown causes' are actually caused by mice or rats.⁵

And another: 25% of fires attributed to "unknown causes" are caused by rodents chewing electrical wires and gas lines.⁴

11. Four steps from probably to actually

Set the first and third side by side.

Probably started by.²

Actually caused by.⁵

11.1 The word actually is doing the opposite of hedging

It asserts that the apparent position is wrong and the real position is this, which is a stronger claim than the original ever made.⁵

11.2 And the same firm's summary line drops the framing entirely

Listing as a hazard that chewed wiring causes an estimated 25% of "unknown cause" house fires.⁵

11.3 And one source firms up the causal language too

From started by, which describes an ignition event, to caused by, which is broader and admits any contribution.²⁴

A chewed wire that shorted is started by. A chewed wire in a building that later burned for another reason is not, and the second phrasing does not distinguish them.

11.4 This is the ordinary life cycle of a statistic

Nobody lies at any step. Each writer slightly firms up what they received, and four transmissions convert an unsourced estimate with a hedge into a fact with an authority.

That is our description and we do not think anybody in the chain acted in bad faith.

12. The logical problem

Which we think is fatal and have not seen raised.

The claim concerns fires whose cause is unknown, undetermined, or mysterious.²⁶

12.1 That category is defined by a failure to determine

A fire enters it because an investigator could not establish what started it.

12.2 So how is the share known

If the cause of each fire in the category is unknown, then no procedure operating on those fires can attribute a quarter of them to a specific cause. The attribution would have to come from somewhere other than the determinations that defined the category.

12.3 The fallacy has a shape

If the cause were determinable the fire would not be in the category, so every fire the claim covers is a fire about which the claim's method could not have spoken.

That is our formulation and it is why §13 says the denominator is doing the work.

12.4 There are ways it could be done

A sample of unknown-cause fires re-investigated to a higher standard. A comparison of unknown-cause rates between rodent-infested and rodent-free building stock. A physical study of what chewed wiring leaves behind after a fire.

Any of those would produce a defensible figure, and none of our sources describes one.

13. Which is not a quibble

Because the category is doing real work in the claim.

Choosing unknown-cause fires as the denominator makes the figure unfalsifiable in the most direct way available: it can only be checked by determining the causes, and if they were determinable the fires would not be in the category.

13.1 Compare a claim about all fires

Rodents cause some share of house fires. That is testable: take fires with determined causes, count the ones attributed to rodent-damaged wiring, and divide.

The answer would be a small number, because determined-cause fires are dominated by cooking, heating, smoking and electrical faults with identified origins. Which may be precisely why the claim is not framed that way, and that suspicion is ours rather than anything we can demonstrate.

13.2 And it makes the number sound larger than the comparable one

A quarter of unknown-cause fires is a smaller absolute quantity than a quarter of all fires, and reads as similar.

Which is our observation and the reason we think the denominator matters as much as the numerator.

14. What a real figure would look like

Stated constructively.

A named study, a defined population of fires, a stated determination procedure, an uncertainty range, and a date.

14.1 None of the five is demanding

They are the ordinary furniture of any quantitative claim, and our articles on allergen action levels and on airtightness standards describe figures that carry all of them.

14.2 The date matters more than it sounds

Section 21 describes a claim that cable materials have changed in a way affecting rodent damage. A figure from an era of different insulation is not a figure about now.

15. A figure that does better

For contrast, from the same search.

Three patent specifications state: in 2005, it was estimated that termites cause over US$50 billion in damage worldwide each year, followed by a named citation.⁷

15.1 A name, a year, and a scope

Which is three of the five items in §14.⁷

15.2 And our earlier article found the weaker version

Our article on guarantees recorded an untraced five billion dollar annual figure for one country, appearing verbatim across several commercial pages.

15.3 And the patents give a second cited figure

That pesticide development was estimated to be about US$256 million per pesticide in 2010 and to take on average about 10 years per pesticide, attributed to a named industry association.⁷

An industry association is an interested party and it is named, which is the distinction this article is about. A reader can weigh a source they can identify.

15.4 So the same subject has a cited figure and an uncited one

And the uncited one is the one in the marketing material.

16. Why the difference matters

Not because one number is right.

We have not read the cited work and cannot say whether fifty billion is a good estimate. What a citation buys is the possibility of checking, which the other figure forecloses.

16.1 And it is the standard this journal has applied throughout

Every article here carries a reference list stating what each source is, what it was used for, and what interest it has. That apparatus exists so a reader can disagree with us on the evidence.

16.2 That is the whole of the argument

A sourced figure can be wrong and remains assessable. An unsourced figure cannot be wrong in any way anybody can demonstrate.

17. And one more unattributed number

Since we were looking.

Rodents invade approximately 21 million U.S. homes each winter.³

17.1 No source given

On the same page as the fire figure.³

17.2 And a further one in a headline

Another firm's article is addressed to a nineteen billion dollar economic impact of rodents, and its text states only that rodents are responsible for a notable percentage of fires of unknown origin, with no figure and no source.⁸

17.3 And the headline number appears only in the address

The article is reachable at a location naming a nineteen billion dollar threat, and the text we read does not state or source that figure anywhere.⁸

Which is a number existing entirely as a headline, and we note it without knowing whether the full article supports it.

17.4 Which is at least honest about its vagueness

A notable percentage claims nothing checkable, where twenty-five per cent claims something checkable and does not support it.

We are not sure which we prefer.

18. The real case, which is stronger

And this is the point of the article.

Rodents demonstrably chew electrical wiring. This is not in dispute, it does not need a statistic, and it is directly observable.

18.1 The trade association's own page supplies the better evidence

Noting that recent news reports from two named cities suggest electrical wiring damaged by rodents was to blame for fires in multifamily communities in these cities.¹

18.2 A named incident is worth more than an unsourced percentage

Because it can be checked, and because it demonstrates the mechanism without requiring anybody to believe a number.

18.3 And the exclusion argument does not need fire at all

Our articles on rodent exclusion justify the work by contamination, structural damage, allergen burden and the difficulty of removing an established population. Fire is an addition to a case that was already sufficient.

18.4 And one source offers a photograph

A firm's page reproduces a fire department account of a house fire where an investigator found wires chewed in the wall with an animal beside them.³

Which is a single anecdote and is the right kind of evidence for the claim actually being made.

19. The mechanism nobody bothers with

Buried in a patent, and better than the usual explanation.

Electrical wiring and electrical conduit generate heat, resulting from the flow of electricity therethrough. While rodents are warm blooded, they are sensitive to decreases in temperature. As a result, rodents are instinctually drawn to heat-producing wires, e.g., electrical wires, as a means to augment their body temperature with heat from the wires.⁶

19.1 And it predicts something the teeth account does not

That damage should concentrate on energised conductors rather than on dead ones, and should rise in cold weather when the temperature differential is greatest.

Both are checkable against the seasonal pattern our own articles describe, and we found nobody testing either.

19.2 That is an explanation of why wires specifically

Rather than an explanation of why rodents gnaw in general.⁶

20. Which is better than the usual explanation

The one every source gives.

That rodents' frontmost teeth (incisors) never stop growing, and to keep them sharp and useful, they have to gnaw on soft objects constantly, so they chew electrical wire.⁵

20.1 The premise is true and the inference is loose

Continuously growing incisors are real. But a rodent with unlimited access to timber, cardboard and insulation has abundant gnawing material and does not need to select a wire.

20.2 The warmth account explains the selection

Which is what needs explaining, and our articles on rodent harbourage describe animals choosing locations by temperature throughout.

That preference is ours between the two accounts and neither source argues it.

20.3 And both can be true

Growing incisors explain why a rodent gnaws at all, and warmth explains which object it selects. The first is a capacity and the second is a preference, which is the distinction this journal has drawn in five other literatures.

20.4 And the patent has an interest

It is arguing for a rodent-repellent cable, so it benefits from a mechanism locating the problem in the cable.⁶ We flag that and still find the reasoning better.

21. And a genuinely interesting hypothesis

From the same document.

It has been postulated that a trend of transitioning from petroleum-based cable components, e.g., jacketing and primary insulation applied directly onto conductors, to more plant-based biodegradable materials, in an effort to reduce waste, has resulted in an increased incidence of rodent-inflicted wire damage, as rodents are supplementing their diets with the plant-based components as a food source.⁶

21.1 Which would make the insulation food

Rather than an obstacle, and would change the behaviour from gnawing through to eating.⁶

21.2 It has been postulated

By whom is again not stated, so this is an unattributed claim in a document we are criticising for unattributed claims.⁶

We report it because it is specific and testable, which the fire statistic is not.

21.3 And it would be testable in a way the statistic is not

Compare rodent damage rates on cables of known composition, or examine whether the shift in materials is reflected in claims data held by insurers and manufacturers.

Which is the difference §14 is about: a claim locating a cause in a material property invites an experiment, and a claim about an undetermined category does not.

21.4 And the same is claimed for vehicles

That rodent-inflicted damage to car wiring systems is becoming increasingly prevalent, attributed to the same material change.⁶

22. Which this journal has met before

Three times, in the same shape.

Our article on the bed bug resurgence concluded that a change made for unrelated reasons removed a control benefit nobody was counting. Our article on treated articles described materials modified for one purpose behaving differently for another. Our article on packaging found film properties determining what an insect could do to it.

22.1 The general form

A material substitution made on environmental grounds alters a pest relationship that was not part of the assessment.

22.2 And it is exactly the kind of claim that needs a source

Which is our complaint about the fire statistic, applied to a hypothesis we find interesting.

23. Why the trade uses the statistic anyway

Honestly, because the answer is obvious.

Fire is the most frightening consequence anybody can attach to a mouse, and a percentage sounds like knowledge.

23.1 Our credence goods article explains the demand

A client cannot evaluate pest control and is looking for a reason to buy. A number with a government attribution supplies one.

23.2 And a percentage feels like a measurement

Which our article on inspection scores made in another context: a number carries an implication of having been counted, whatever produced it.

23.3 And the incentive to check is nil

Nobody in the chain gains from tracing it, and everybody gains from repeating it, which is the condition under which an unsourced figure survives indefinitely.

24. And what it costs

Three things, and the third is the serious one.

It is checkable and fails. Anybody who follows the trail finds what §4 found.

It displaces the better argument. Section 18.

And it makes the trade's other claims harder to believe. A reader who discovers one figure is unsupported has reason to discount the next one.

24.1 And there is a fourth cost, to the client

A homeowner who buys rodent exclusion because of a fire figure has bought it on a reason that may not hold, when better reasons were available and would have justified the same purchase.

The work was worth doing. The argument that sold it was not the one that made it worth doing.

24.2 Which is the general cost of an unsourced claim

It spends credibility that the sourced claims need.

25. Our own position

The disclosure, and it is direct.

We have used figures of this kind. Not this one specifically, so far as we can establish, but the general practice of quoting an industry statistic without checking its origin is one this business has engaged in.

25.1 And the fire argument is commercially powerful

Rodent exclusion sells better against a fire risk than against contamination, and this article removes a tool we could otherwise use.

25.2 Which is the pattern of the last several articles

Our guarantee article questioned our own contract term, our sanitation article questioned our own advice, and our inspection score article questioned our own strongest sales argument. This is the fourth.

26. What we will do instead

Two commitments.

No statistic we cannot trace. If we cannot find where a figure came from, we will not quote it, which on current evidence removes most of the industry's standard numbers.

And the observable case instead. Chewed wiring found during an inspection is evidence a client can look at, and it makes the argument §18 says is the better one without requiring anybody to trust a percentage.

26.1 And an explicit test for ourselves

Before quoting any figure: who produced it, from what, and when. If we cannot answer all three, it does not go in a report or on the site.

Which is §14 applied to us rather than to the industry, and it is the only version of this article that costs us anything.

26.2 Which is weaker rhetorically

And we would rather be weaker and checkable.

27. The Manitoba position

Brief, and mostly a gap.

Every figure in this article is American. Fire investigation practice, cause classification and reporting differ by jurisdiction, and we have no reason to think a figure derived from one system transfers to another.

27.1 What we could not find

Any Canadian or Manitoba figure for rodent-attributed fires, any provincial fire commissioner analysis of undetermined-cause fires, and any local damage estimate for any pest.

27.2 And the material argument may transfer better than the statistic

Section 21's claim about plant-based cable insulation concerns products sold across North America, so if it is true here it is true in the same way. A material change does not stop at a border.

27.3 And the local fire data exists

Fire investigation is a provincial function and undetermined-cause fires are recorded. Whether anybody has looked at them for this purpose is a question we cannot answer and would like to.

28. Limitations and open questions

We may simply have missed the source. A figure this old could rest on a study from before the material we can reach online, and absence from our search is not absence from the literature.

And the original may exist in print. Fire service and extension publications from the middle of the last century are largely not digitised, so a figure entering circulation before the web would leave exactly the trail we found.

That is the most important caveat here and we state it plainly rather than claiming the statistic is fabricated.

Every source in this article is commercial, governmental or a patent. Four pest control firms, a trade association, a state health department and two patent specifications.¹⁶

We did not read the cited termite work. Only the patents' citation of it.⁷

And we did not examine fire investigation practice. How undetermined-cause fires are classified, what proportion of fires they represent, and whether any jurisdiction re-examines them are all questions we would need answered before §12 could become a finding rather than an objection.

Sections 1.2, 3.1, 6.3, 8.2, 9, 11, 12, 13, 14, 16, 17.3, 18.2, 20, 22, 23, 24, 25 and 26 are our reasoning. The trail reconstruction, the attributed-denominator observation, the laundering analysis, the hedge-stripping sequence, the logical objection to the denominator, and the argument that the observable case is stronger are ours rather than sourced positions.

29. Conclusion

A state health department states that it is estimated 25 per cent of fires attributed to unknown causes are probably started by rodents, and cites nobody.² A national trade association states that it is estimated rodents are responsible for 20 to 25 per cent of such fires, in the sentence immediately after a precisely attributed quotation giving 46,500 electrical home fires, 420 deaths, 1,520 injuries and 1.5 billion dollars of damage, and cites nobody for the rodent share.¹ One pest control firm attributes the figure to the health department, another to a trade magazine issue, and a third writes that approximately a quarter of such fires are actually caused by mice or rats.⁴³⁵ Four transmissions carry it from probably to actually and attach a government authority on the way.

Underneath the provenance problem is a logical one. The claim concerns the category of fire defined by an investigator having been unable to determine the cause, and no procedure operating on those determinations can then assign a quarter of them to rodents. The figure could be established by re-investigating a sample, or by comparing undetermined-cause rates between infested and uninfested building stock, and no source we found describes anything of the kind. Choosing that denominator also makes the claim unfalsifiable in the most direct way available, since checking it would require determining the causes of fires classified as undeterminable.

None of which is necessary, because the underlying claim is true and observable. Rodents chew electrical wiring, fire investigators find chewed wiring, and the trade association's own page supplies named incidents in two cities that make the point without a percentage.¹ The strongest material we found in this search was not a statistic at all: a patent's account of why rodents select wires specifically, because energised conductors are warm and a warm-blooded animal sensitive to cold is drawn to them.⁶ That is an explanation rather than a number, it is checkable against everything our own articles say about how rodents choose where to be, and it does what the statistic was recruited to do without spending any credibility to do it.

References

1. Pests under fire, best practices for pest-proofing your community, article on a national pest management association's commercial pest news site, reproduced from a property management magazine. Trade association source, cited as attributed material. Used for its quotation of a named fire protection association that fire departments responded to 46,500 reported home structure fires involving electrical failure or malfunction in 2010, resulting in 420 civilian deaths, 1,520 civilian injuries and 1.5 billion dollars in direct property damage; for the immediately following unattributed statement that it is estimated rodents are responsible for 20 to 25 per cent of all fires of unknown causes because of their propensity for chewing electrical wiring and gas lines; for the note that recent news reports from two named cities suggest electrical wiring damaged by rodents was to blame for fires in multifamily communities there; for the listing of improperly sealed attic vents among the access points property managers should address; and for the recommendation that property managers work with a pest management professional to conduct exclusion and an analysis of conducive conditions. https://www.pestworld.org/commercial-pest-news/pests-under-fire-best-practices-for-pest-proofing-your-community-units-magazine/
2. Municipal rodent management page, state department of public health. Government source, cited as attributed material, and carrying the central figure without attribution. Used for the statement that a typical large city in that country annually receives more than 10,000 complaints about rodent problems and performs tens of thousands of rodent control inspections and baiting services; for the account that rodents consume and contaminate food, that burrowing causes streets and structures to collapse, and that gnawing has caused power outages, internet blackouts, computer crashes, fires and human deaths; for the unattributed statement that it is estimated 25 per cent of all fires attributed to unknown causes are probably started by rodents gnawing on gas lines, electrical wiring and matches; and for the description of long-term urban rodent control as combining sanitation, exclusion and, when necessary, traps and baits, with an inspection made and pests identified before control is implemented. https://dph.illinois.gov/topics-services/environmental-health-protection/structural-pest-control/municipal-rodent-management.html
3. Rodent damage, frayed wires and house fires, article by a wildlife and rodent control company. Commercial source, cited as attributed material. Used for the statement, attributed there to a 2012 issue of a trade association magazine, that rodents and home fires may be related in some cases and that current estimates attribute rodents as responsible for 20 to 25 per cent of fires with unknown causes; for the unattributed claim that rodents invade approximately 21 million homes in that country each winter; for the accompanying fire department account of a house fire in which an investigator found wires chewed in the wall with an animal beside them; and for the note that December and January are peak months for home fires. https://www.crittercontrol.com/wildlife/rodents/rodent-caused-house-fires/
4. Mice cause 25 per cent of mystery fires, blog article by a pest control company. Commercial source, cited as attributed material and quoted here as an example of downstream attribution. Used for its statement that according to the named state department of public health, 25 per cent of fires attributed to unknown causes are caused by rodents chewing electrical wires and gas lines; for its advice that commercial property purchasers have an inspector check for rodent activity; for its note that dirt crawlspaces are particularly vulnerable since rodents can tunnel under the skirting; and for its observation that distinguishing an old rodent problem from a fresh infestation is difficult because droppings dry quickly, with scent and the appearance of chew marks offered as the better method. https://parkerecopestcontrol.com/2019/01/30/infestation-inferno-mice-cause-25-of-mystery-fires/
5. The dangers of having mice and rats in your home, blog article by a pest control company. Commercial source, cited as attributed material and quoted here for its phrasing. Used for the statement that approximately 25 per cent of house fires attributed to unknown causes are actually caused by mice or rats; for the summary hazard line that chewed wiring causes an estimated 25 per cent of unknown cause house fires; for the explanation that rodents' incisors never stop growing so they must gnaw on soft objects constantly, chewing through electrical wire, furniture, storage material and insulation; and for the account that damaged wiring sparks and overheats, which can start electrical fires. https://plunketts.net/blog/how-rodents-hurt-houses
6. Method of manufacturing a rodent repellent cable, patent specification. Commercial advocacy for the claimed invention, with a direct interest in locating the problem in cable materials, and flagged accordingly. Used for the unattributed statement that twenty per cent of fires of undetermined origin are attributed to short circuits caused by rats chewing on the insulation of electrical wiring; for the account that electrical wiring and conduit generate heat from the flow of electricity, that rodents though warm blooded are sensitive to decreases in temperature, and that as a result they are instinctually drawn to heat-producing wires as a means to augment their body temperature; for the note that rodents chewing wires cause power outages or fires and present a danger of contact with exposed live wires; and for the postulated hypothesis that a trend of transitioning from petroleum-based cable jacketing and primary insulation to more plant-based biodegradable materials, in an effort to reduce waste, has resulted in an increased incidence of rodent-inflicted wire damage as rodents supplement their diets with the plant-based components, with the same explanation offered for increasingly prevalent damage to car wiring systems. https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/10910129
7. Molecules having pesticidal utility, patent specification, one of three carrying identical background text. Commercial advocacy for the claimed invention, flagged accordingly, though the figure it reports does carry a citation. Used for the statement that termites cause damage to all types of private and public structures as well as agricultural and forestry resources; for the estimate, dated to 2005 and followed by a named citation, that termites cause over 50 billion United States dollars in damage worldwide each year; and for the associated figures attributed to an industry association that pesticide development was estimated to cost about 256 million dollars per pesticide in 2010 and to take on average about ten years per pesticide. https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/9661853
8. The economic burden of rodents, blog article by a pest control company. Commercial source, cited as attributed material. Used for its statement that rodents are responsible for a notable percentage of fires of unknown origin due to their tendency to gnaw on electrical wires, given without a figure or a source; for its observation that this can lead to economic losses from property damage and increased insurance premiums; and for its recommended prevention strategies of sealing entry points, maintaining cleanliness and conducting regular inspections. https://www.newgenpestcontrol.ca/blog/the-19-billion-threat-the-economic-impact-of-rodents-on-the-u-s