Part 22
Fires in mills or warehouses have sometimes been traced to the spontaneous ignition of oily or fatty rags and waste carried under floors by rats. Cotton and woolen mills are said to be peculiarly subject to fires of this kind.
Sometimes rats cause fires by gnawing through the lead pipes leading to the gas meter. Workmen or others, searching for the leak, accidentally ignite the gas. Phillips’s warehouse, London, was twice badly damaged by fires originating in this way, and in several instances the sleeping inmates of houses have been in danger of asphyxiation by gas freed in this manner.
The most common way in which rats and mice cause fires is by the destruction of the covering of electric light wires under floors or in partition walls. A considerable percentage of the enormous fire losses in the United States is caused by defective insulation of wires. After wires are once in position rats are the chief agents in impairing the insulation. These animals do much mischief also by gnawing off the coverings of telephone wires. In the case of electric light wires the covering is probably used by the rats for nesting material, but frequently the paraffin in the insulation is the object of attack.
BUILDINGS AND FURNITURE.
Rats seem to be able to gnaw through almost any common material except stone, hard brick, cement, glass, and iron; neither wood nor mortar suffice to keep them out of bins or rooms. They sometimes gnaw through walls or doors in a single night. In the same way they enter chests, wardrobes, bookcases, closets, barrels, and boxes. Almost every old dwelling bears evidence of its present or former occupancy by rats. Often the depreciation of houses and furniture is largely due to marks left upon them by rats—marks that paint and varnish can not hide.
Damage to dwellings by rats is a large item. The decay of sills and floors is hastened by contact with moist soil brought up from rat burrows. Ceilings, wall decorations, and floor coverings are flooded by leaks in lead pipes or wooden tanks gnawed by rats. Bricked areas and even foundations are undermined and ruined by rats. All this is real waste and a constant drain on the resources of the country.
MISCELLANEOUS.
A few instances of miscellaneous damage by rats may be mentioned to show the great variety of mischief chargeable to the animals.
A Washington, D. C., merchant reported that at one time rats in his store destroyed 50 dozen brooms worth $2.50 a dozen. In another store, in a single night, they broke $500 worth of fine chinaware on shelves and tables. A dealer in harness reported the loss of $400 worth of collars in one season. The manager of a restaurant complained of an average loss of $30 a month in table linen ruined by rats and mice. A hotel reported the destruction of $75 worth of linen in a month.
At Mobile, Ala., in March, 1908, lost jewelry worth $400 was recovered from a rat’s nest in the home of Señor Viada.
In London rats at one time killed all but 11 out of an aviary of 366 birds.
At Hamburg, Germany, Carl Hagenbeck once had to kill three young African elephants because rats had gnawed their feet, inflicting incurable wounds.
Rats often gnaw the hoofs of horses until they bleed. They kill young lambs and pigs, and have been known to gnaw holes in the bodies of very fat swine, causing death.
Like the muskrat, the brown rat often burrows into embankments and dams, causing serious breaks.
The rat is one of the greatest enemies with which the sugar planter has to contend, destroying acres of growing cane.
In rice plantations rats not only break down and destroy the growing crops, but burrow into the dikes and flood the fields at the wrong season.
On the London docks and on shipboard ivory is often badly damaged by rats. They select for attack the greenest tusks, which are the more valuable.
Mail sacks and other kinds of bagging are greatly injured by rats. The consequent loss and necessary outlay for repairs are a large item in post-office expenditures and in mills and other places where bagging is used.
About the year 1616 rats caused a two years’ famine in the Bermudas. In the southern Deccan and Mahratta districts of India rats ate a large part of the scant crops of 1878 and 1879, and were regarded as in a great measure responsible for the severe famine which followed.[CH] A writer in Chambers’s Journal stated that the Dutch abandoned the Isle of France (Mauritius) in 1610 because of the great abundance of rats.[CI]
Footnote CH:
Brit. Med. Journ., p. 623, September 15, 1905.
Footnote CI:
Chambers’s Journal, vol. 21, p. 244, 1854.
AMOUNT OF LOSSES CAUSED BY RATS.
The damage done by a single rat varies greatly with the circumstances. We have already stated that the cost of feeding a rat on grain varies from 60 cents to $2 a year. Assuming that much of the rat’s food is waste, each rat on a farm will cause a loss of over 50 cents a year. In cities the damage by a single rat probably averages more than in the country. Hotel managers and restaurant keepers state that $5 a year is a low estimate of the loss inflicted by a rat. In making an estimate it should be remembered that the rat is to be charged not only with the food it actually consumes but also with what it destroys or pollutes and renders unfit for use.
If an accurate census of the rats in the United States were possible, and if the minimum average loss caused by a rat were known, an estimate of the total annual losses from their depredations could be made. It was on such a minimum basis that the Incorporated Society for the Destruction of Vermin arrived at their total estimate of £15,000,000 ($73,000,000) as the yearly losses from rats in Great Britain and Ireland. Three propositions were assumed: first, that in cities and villages the number of rats equals the population; second, that in the country there is at least one rat for every acre of cultivated land; third, that each rat in the kingdom inflicts a damage of at least a farthing per day. Circulars asking whether these assumptions are excessive were distributed throughout the country. From 90 to 99 per cent of the replies fully indorsed each of the assumptions.
It can readily be seen that the English basis of estimate would not apply to farm conditions in the United States, where the area in the twelve leading crops alone is over 250,000,000 acres. On a basis of a rat per acre and damage of a farthing per day the annual loss on this area would be $450,000,000, a sum much too great for serious consideration. However, in the more thickly populated parts of the country an estimate of one rat per acre would not be excessive; and it is probable that in most of our cities there are quite as many rats as people. Yet it would be unsafe, owing to our vast territory and varying conditions, to make these assumptions the basis for conclusions.
Over a year ago the writer made an attempt to investigate actual conditions, and thus arrive at an estimate of the total damage by rats in the cities of Washington and Baltimore. From the data obtained the direct annual damage in the two cities was calculated at $400,000 and $700,000, respectively. The Census Bureau in 1906 estimated the population of these cities at 308,000 and 554,000, respectively. If the estimates of damage were correct, the average loss for each person is $1.27 a year; and, on the same basis, the 28,000,000 of urban population in the United States (census of 1900) sustains an annual direct injury of $35,000,000 from rats. This is considerably lower than on the English assumption, which would make the losses in our cities over $50,000,000.
Denmark (population 2,500,000) has an estimated rat bill of about $3,000,000 a year, or $1.20 a person. Germany (population 56,000,000) is said to sustain a loss from rats of 200,000,000 marks ($47,640,000) a year, or about 85 cents for each person. The per capita estimate for the United Kingdom is about double that made for Germany. In France the loss from rats and mice for a single year (1904) was placed at $38,500,000, or a little over a dollar for each of its 38,000,000 inhabitants. These estimates are supposed to include only direct losses, but they vary enough to show that no common basis can be assumed for all countries. With present information, therefore, any attempt to state the amount of loss from rats in the United States would be largely guesswork. Considering the population and wealth of the country, however, and the vast area over which rats are abundant, it is not unreasonable to conclude that in the United States the losses from rats amount to much more than in any of the other countries named.
INDIRECT LOSSES.
To the direct losses caused by rats must be added the cost of fighting the animals and of protecting property from them. In our larger cities a number of so-called expert rat catchers are to be found, who operate with dogs, ferrets, traps, poisons, or other means, and who have an extensive clientage among merchants, hotel managers, and others. These pay the rat catcher a yearly or monthly stipend to keep their premises free of rats and mice. Some of the large establishments pay $200 to $600 yearly for such service. While the agreements are seldom kept in full, the clients are usually satisfied that results warrant the expense. Even when no contractor is employed, merchants are at expense for traps, poisons, the keep of cats or dogs, and other means of fighting rats. The same is true in less degree of nearly every householder.
The cost of protecting property from rats is no small item. It increases the expense of nearly all building, but it greatly reduces direct losses from the animals. The economy of rat-proof construction is everywhere manifest, in city or country, and the necessity for it can not be too strongly emphasized.
Depreciation of property and loss of rents and custom are items not generally thought of in connection with rat damage. A few years ago the writer knew of almost an entire block of city houses that remained untenanted for several months, because infested by rats. As the houses were otherwise desirable, the loss of rent to the owners was probably nearly $2,000. The presence of rats in markets, hotels, and restaurants inevitably results in loss of custom, besides the direct damage by the rodents.
From every point of view the keeping of rats is exceedingly expensive, and the sooner our population can be made to realize the enormous drain upon our resources caused by these rodents the sooner can concerted measures for their destruction be made effective.
THE RAT IN RELATION TO INTERNATIONAL SANITATION.
By Asst. Surg.-Gen., JOHN W. KERR,
_Public Health and Marine-Hospital Service_.
Rats, like man, had their origin in Asia, from which continent they have finally become disseminated throughout the world. They, too, like man, are great travelers, and therefore prey on the commerce of the ships in which they are carried. For this reason, and on account of the fact that they are subject to plague and may transmit the disease from one country to another, these animals have an influence on international policy, and their control aboard ships is an international problem.
It has been estimated that there are as many rats as there are human beings, and that each rat causes each day a loss by the destruction of material of at least half a cent.
Assuming that the rat population aboard ships is as great as the human population—and my experience gained during the fumigation of ships to kill rats convinces me that on the whole it is greater—some idea may be had of the enormous migrations of rats and the toll they exact for food from international commerce. Some idea can also be had of the danger of rats in transmitting plague when it is remembered that 51 countries have been infected with the disease since the present pandemic began in Canton, China, in 1894, and when it is known that at least 146 ships have had plague infection on board during that time.
During the International Sanitary Conference of Paris in 1903 the influence of the rat in transmitting plague was borne in mind, and the international sanitary agreement, which was signed ad referendum December 3, 1903, requires the destruction of rats aboard plague-infected ships, recommends it on ships suspected of being plague infected, and permits it on ships indemne from plague. The ship is considered indemne from plague which, although coming from an infected port, has had neither death nor case on board either before departure, during the voyage, or at the moment of arrival.
The International Sanitary Convention signed at Washington, October 14, 1905, follows the text of the Paris convention, with respect to plague, consequently embodying similar requirements and recommendations as follows:
ART. XX. _Classification of ships._—A ship is considered as infected which has plague, cholera, or yellow fever on board, or which has presented one or more cases of plague or cholera within seven days, or a case of yellow fever at any time during the voyage.
A ship is considered as suspected on board of which there have been a case or cases of plague or cholera at the time of departure or during the voyage, but no new case within seven days; also such ships as have lain in such proximity to the infected shore as to render them liable to the access of mosquitoes.
The ship is considered indemne which, although coming from an infected port, has had neither death nor case of plague, cholera, or yellow fever on board, either before departure, during the voyage, or at the time of arrival, and which in the case of yellow fever has not lain in such proximity to the shore as to render it liable, in the opinion of the sanitary authorities, to the access of mosquitoes.
ART. XXI. Ships infected with plague are to be subjected to the following regulations:
1. Medical visit (inspection).
2. The sick are to be immediately disembarked and isolated.
3. Other persons should also be disembarked, if possible, and subjected to an observation,[CJ] which should not exceed five days, dating from the day of arrival.
Footnote CJ:
The word “observation” signifies isolation of passengers, either on board ship or at a sanitary station, before being given free pratique.
4. Soiled linen, personal effects in use, the belongings of crew[CK] and passengers which, in the opinion of the sanitary authorities are considered as infected, should be disinfected.
Footnote CK:
The term “crew” is applied to persons who may make, or who have made, a part of the personnel of the vessel and of the administration thereof, including stewards, waiters, “cafedji,” etc. The word is to be construed in this sense wherever employed in the present convention.
5. The parts of the ship which have been inhabited by those stricken with plague, and such others as, in the opinion of the sanitary authorities, are considered as infected, should be disinfected.
6. The destruction of rats on shipboard should be effected before or after the discharge of cargo, as rapidly as possible, and in all cases with a maximum delay of forty-eight hours, care being taken to avoid damage of merchandise, the vessel, and its machinery.
For ships in ballast, this operation should be performed immediately before taking on cargo.
ART. XXII. Ships suspected of plague are to be subjected to the measures which are indicated in Nos. 1, 4, and 5 of Article XXI.
Further, the crew and passengers may be subjected to observation, which should not exceed five days, dating from the arrival of the ship. During the same time the disembarkment of the crew may be forbidden, except for reasons of duty.
The destruction of rats on shipboard is recommended. This destruction is to be effected before or after the discharge of cargo, as quickly as possible, and in all cases with a maximum delay of forty-eight hours, taking care to avoid damage to merchandise, ships, and their machinery.
For ships in ballast this operation should be done, if done at all, as early as possible, and in all cases before taking on cargo.
ART. XXIII. Ships indemne from plague are to be admitted to free pratique immediately, whatever may be the nature of their bill of health.
The only regulation which the sanitary authorities at a port of arrival may prescribe for them consists of the following measures:
1. Medical visit (inspection).
2. Disinfection of soiled linen, articles of wearing apparel, and the other personal effects of the crew and passengers, but only in exceptional cases when the sanitary authorities have special reason to believe them infected.
3. Without demanding it as a general rule, the sanitary authorities may subject ships coming from an infected port to a process for the destruction of the rats on board before or after the discharge of cargo. This operation should be done as soon as possible, and in all cases should not last more than twenty-four hours, care being taken to avoid damaging merchandise, ships, and their machinery, and without interfering with the passing of passengers and crew between the ship and the shore. For ships in ballast this procedure, if practiced, should be put in operation as soon as possible, and in all cases before taking on cargo.
When a ship coming from an infected port has been subjected to a process for the destruction of rats, this process should only be repeated if the ship has touched meanwhile at an infected port, and has been alongside a quay in such port, or if the presence of sick or dead rats on board is proven.
The crew and passengers may be subjected to a surveillance, which should not exceed five days, to be computed from the date when the ship sailed from the infected port. The landing of the crew may also, during the same time, be forbidden except for reasons of duty.
Competent authority at the port of arrival may always demand, under oath, a certificate of the ship’s physician, or in default of a physician, of the captain, setting forth that there has not been a case of plague on board since departure, and that no marked mortality among the rats has been observed.
ART. XXIV. When upon an indemne ship rats have been recognized as pest stricken as a result of bacteriological examination, or when a marked mortality has been established among these rodents, the following measures should be applied:
1. Ships with plague-stricken rats:
(_a_) Medical visit (inspection).
(_b_) Rats should be destroyed before or after the discharge of cargo, as rapidly as possible, and in all cases with a delay not to exceed forty-eight hours; the deterioration of merchandise, vessels, and machinery to be avoided. Upon ships in ballast, this operation should be performed as soon as possible, and in all cases before taking on cargo.
(_c_) Such parts of the ship and such articles as the local sanitary authority regards as infected, shall be disinfected.
(_d_) Passengers and crew may be submitted to observation, the duration of which should not exceed five days, dating from the day of arrival, except in special cases, where the sanitary authority may prolong the observation to a maximum of ten days.
2. Ships where a marked mortality among rats is observed:
(_a_) Medical visit (inspection).
(_b_) An examination of rats, with a view to determining the existence of plague, should be made as quickly as possible.
(_c_) If the destruction of rats is judged necessary, it shall be accomplished under the conditions indicated above in the case of ships with plague-stricken rats.
(_d_) Until all suspicion may be eliminated, the passengers and crew may be submitted to observation, the duration of which should not exceed five days, counting from the date of arrival, except in special cases, when the sanitary authority may prolong the observation to a maximum of ten days.
ART. XXV. The sanitary authorities of the port must deliver to the captain, the owner, or his agent, whenever a demand for it is made, a certificate setting forth that the measures for the destruction of rats have been efficacious and indicating the reasons why these measures have been applied.
To be in conformity with these agreements regarding the destruction of rats, quarantine authorities may demand the fumigation of infected and suspected ships; suspected ships within the meaning of the treaties being those on board of which there have been a case or cases of plague at the time of departure or during the voyage, but no new case within seven days. In the case of indemne ships, on the other hand, without demanding it as a general rule, the sanitary authorities may subject them to fumigation to kill rats. When upon such ships rats have been recognized as pest stricken, as a result of bacteriological examination, or when a marked mortality has been established among these rodents, fumigation is prescribed.
While the classification of ships and the limitations placed on quarantine procedures in relation thereto, as contained in existing international sanitary agreements, is more apparent than real, there appears to be a lack of exactness with respect to the destruction of rats necessary for the prevention of the importation of plague from one country to another.
Since the adoption of the international sanitary agreement of Paris in 1903, some of the unproven convictions of that time regarding the rôle of rats and fleas in the transmission of plague have been proven to be positive facts. Many epidemiological observations and exact scientific experiments have demonstrated particularly the importance of the rat in the propagation of plague and the rôle of the flea as the carrier of infection from rat to rat and from rats to man.
At the same time there has been a growing conviction that other agencies, such as passengers, baggage, and merchandise play a very minor rôle in the dissemination of plague. It is of interest, therefore, to review the efforts being made at the more important seaports to exterminate rats, as well as the methods being employed to that end.
INQUIRY INTO THE CRUSADE AGAINST RATS THROUGHOUT THE WORLD.
The first law in modern times aiming at the destruction of rats appears to have been enacted in Barbados in 1745.[CL] According to Boelter this act was incorporated into a new act which was passed in 1748. The same author states that the next legislative body to enact a law against rats was in Antigua in 1880. In the same article he refers to the rat ordinance of Hongkong, adopted in 1902.
Footnote CL:
W. R. Boelter, “On Rat Laws,” Journal of Incorporated Society for the Destruction of Vermin, October, 1908.
Private measures against rats have undoubtedly been practiced from time immemorial. The action of Denmark, however, in passing a law for the systematic destruction of rats and providing the organization for that purpose is perhaps the most notable advance taken on this subject. A copy of the Danish law appears elsewhere in this publication.
That the citizens of other countries are equally alive to the importance of rat extermination is shown by the fact that in England there exists an incorporated society for the destruction of vermin, which society in October, 1908, began the publication of a journal which would supply trustworthy information upon the subject.