M. C. Betts

“ Modern structures are so nearly rat proof that to make them completely so requires only slight and inexpensive changes. Furthermore, rat proofing is closely associated with fire stopping and with sanitary measures that are now required by law in many places. Cities in growing numbers have added rat proofing clauses to their building ordinances with such good effect that others are sure to follow their lead. Builders should therefore compare the cost of rat proofing during construction with the probable later cost, in case local laws should require that all buildings be made rat proof. ”

“ Scrupulous cleanliness is essential in markets, but even where this is practiced it is not possible completely to eliminate rat food, so the main reliance must be placed on the removal of all rat harbors. Not only must the building in which the market is housed be rat proofed, but also all the fixtures. In old public markets the stalls were frequently constructed as if designed for the protection of rats. Dark, out-of-the-way holes under counters, stands, and shelves afford convenient places for the accumulation of trash, which it would be well to destroy ”

“ Rat proofing, however, is at last making definite headway against the age-old enemy of mankind, and it is upon this that the ultimate solution of the rat problem will depend.
The destruction of rats for temporary relief and for keeping them under control in places where rat proofing is not possible or practicable will always be necessary, and knowledge of the best means of destroying rats is essential to any rat-control program. ”

“ A rat-proof farm is not necessarily one in which the entire farmstead is absolutely proofed, but rather one where conditions are so unfavorable for any invading rats that they either will desert the premises of their own accord or may be easily routed by man or dogs. The source of the trouble on almost any heavily rat-infested farm can be traced directly to conditions that furnish rats safe refuges near abundant food. The commoner of these rat-breeding places are beneath wooden floors set a few inches off the ground in poultry houses, barns, stables, granaries, corncribs, and even residences ”

“ Had such ordinances been enacted 50 years ago and rigidly enforced since that time the large majority of buildings to-day would be rat proof, and rats, with their accompanying filth and destructiveness, would have been largely eliminated. There would also be fewer of the unsightly and insanitary shacks now existing in most cities, and the average structure would be of a more desirable type. As modern construction conforms so closely in principle to the requirements of rat proofing, there should be little, if any, opposition among builders to a rat-proofing clause in building ordinances. ”

“ In rat proofing a city building it is well first to look to the exterior. If the locality is heavily infested with rats, some are almost certain sooner or later to find their way into the building however well protected against them it may be. Garbage and trash usually comprise the bulk of the rats' food supply. A metal, water-tight garbage can, large enough to contain all garbage accumulations between collections and having a close-fitting lid (fig 1) , is of prime importance and should be required in all cases by city law. ”

“ Neatness is of prime importance in keeping a place free from, rats, and providing facilities for keeping it neat should be considered part of the rat-proofing program. An incinerator, which can be made from a discarded metal drum or rolled-up poultry netting, is convenient for burning all trash and combustible waste; and a deep, covered pit with a trapdoor will take care of tin cans and other noncombustibles, if it is not practicable to haul them away at regular intervals. A covered garbage can is also indispensable on farms where table scraps are not fed directly to poultry or hogs. ”

“ Every separate structure presents its individual problem, but there are two general principles that apply in all cases and that should be kept in mind when the rat proofing of any building is being considered. ”

“ Public, farmers', and wholesale markets, commission houses, and similar places where vast quantities of foodstuffs are assembled and redistributed are nearly always infested with large numbers of rats. Such structures are usually concentrated in districts, and these often become rat-breeding centers, from which the rats constantly overflow to adjoining sections of the city. Rat proofing a district of this kind would seem to be almost hopeless, yet it has often been demonstrated that the task is not only feasible but entirely practicable. ”

“ Rat proofing the city is a responsibility of the city government. The greatest force that can be exerted to-day toward the permanent suppression of the rat pest is through the passage of practical building ordinances that require the rat proofing of buildings and the adoption of sanitary regulations that will insure clean premises and adequate collection and disposed of garbage. ”

“ First, the exterior of those parts of the structure accessible to rats, including porches or other appurtenances, must be constructed of materials resistant to the gnawing of rats, and all openings must be either permanently closed or protected with doors, gratings, or screens; second, the interior of the building must provide no dead spaces, such as double walls, spaces between ceilings and floors, staircases, and boxed-in piping, or any other places where a rat might find safe harborage, unless they are permanently sealed with impervious materials. ”

“ The use of concrete in the construction of most farm buildings is usually the best means of permanently excluding the rat. Fortunately, many of the fundamentals of rat proofing are also principles of good construction. As am example, in order to support a building properly, the foundation should extend well into the ground below the frost line; rat proofing likewise requires that the foundation wall extend at least 2 feet below the surface. Rats seldom burrow deeper than 2 feet unless natural passageways assist. ”

“ It is seldom possible to shut out rats completely from barns or entirely to cut off their food supply where livestock is fed. Little trouble will be experienced with them, however, if their harbors are eliminated. In barns rat harbors are most frequently found around stalls, under wooden mangers, and stall partitions, and beneath wooden or dirt floors. In modern barns with concrete floors, concrete or metal mangers, and metal stanchions, such places of retreat are entirely eliminated. ”

“ In one city in which rat proofing has been vigorously prosecuted for a number of years and in which more than 80 per cent of the old buildings have been made proof against rats, the sharp decline in the number of fires resulted in a 5 per cent reduction in the fire-insurance rates. More than $1,000,000 was spent in the same city in rat proofing 10 miles of docks, but even this large expenditure was found to be a profitable investment. ”

“ Probably nothing so nearly reflects the sanitary conditions of a city as the number of rats that it harbors, for the rat population is usually in inverse ratio to the degree of sanitation maintained. In 1930 at least 13 cities in this country had rat-proofing laws, and more than 30 others had fire-stopping requirements that are important in rat proofing. ”

“ Such a loss would go far toward rat proofing any premises. A common cause of rat depredations in warehouses is the construction of platforms a few inches off the floor upon which to pile flour and other produce. Such platforms provide permanent shelter for rats and should be eliminated. Boards may be laid flat on the concrete floor with no spaces between them to afford rat harbors; or, if this is not sufficient proof against dampness, the platforms should be raised a foot or more off the floor to admit light. In such a place a rat does not feel safe and will not stay. ”

“ An effective rat-proofing program must be practicable and not too drastic; otherwise it will fail from lack of popular support. Attempts to enforce rat proofing of existing structures would probably not be feasible unless under stress of an outbreak of bubonic plague or other rat-borne disease epidemic. There seems to be no good reason, however, why buildings constructed in the future or remodeled should not be made rat proof under the requirements of building ordinances. ”

“ Many men have devoted their lives to a study of methods of rat control, and as a result countless preparations, devices, and contrivances are constantly being made available. Trapping, snaring, trailing, flooding, digging, hunting, ferreting, poisoning, and fumigating are employed, and rat limes, rat lures, rat repellents, and bacterial viruses are resorted to, and even antirat laws, local. ”

“ Class A.—All buildings, outhouses, and other superstructures of class A shall have floors made of rat-proof material or of concrete, which concrete shall be not less than 3 inches thick, and overlaid with a top dressing of cement, mosaic, tiling, or other impermeable material laid in cement mortar, and such floor shall rest without any intervening space between upon the ground or upon filling of clean earth, sand, cinders, broken stone or brick, gravel, or similar material, which filling shall be free from animal or vegetable substances ”

“ Large piles of cut stove wood on many northern farms become rat infested. The same is true of manure piles adjoining barns and, to a lesser extent, of hay and straw stacks near farm buildings. These do not provide food and are attractive to rats for harbors only if near a source of food supply; moving them to a place at some distance from where foodstuffs are handled will usually solve the problem. ”

“ Another common source of rat trouble, particularly in the northern half of the United States, is the hollow wall, within which rats find safe retreat and convenient runways leading to the haymow. In recent years fibrous insulating materials have been used to line the interiors of many farm buildings, and in most cases these have resulted in greatly increased rat infestation. Rats cut through these composition boards very easily and seem to be attracted by the facilities for breeding thus provided. ”

“ All feed bins shall be constructed of cement, stone, metal, or wood, and with close-fitting doors. If constructed of wood, the bins shall be lined or covered with metal, and the whole so constructed as to prevent the ingress or egress of rats. All grain, malt, and other animal food, except hay, stored or kept in any stable, must be kept in such feed bins. ”

“ It is important that concrete be hard, as weak concrete is but a slight obstacle to the sharp rodent incisors. The mixture approved for ordinary building construction, however, is sufficiently hard to be entirely rat proof, and it is essential that approved practices of mixing and placing concrete be followed. Directions for using concrete and for building concrete floors are given in Farmers' Bulletin 1279, Plain Concrete for Farm Use, and in Farmers' Bulletin 1480, Small Concrete Construction on the Farm. ”

“ Ditch banks often are a source of rat infestation, but in most climates during the warmer months only. The rodents concentrate in such places because they are less likely to be disturbed there. Rat proofing the ditch bank consists merely of burning or otherwise destroying the protective vegetation. This, of course, affords only temporary relief and should not be considered strictly rat proofing. ”

“ Warehouses require rat proofing because of the great quantities of foodstuffs handled there and even stored for long periods. It is essential that the building itself be rat proofed with concrete or masonry foundation, concrete floors, and tight-fitting doors lined with metal at the base. ”

“ Basement ceilings, when accessible to rats, cause much trouble, and frequently the best remedy is to remove them entirely. In frame construction spaces between studs in walls opening into basements also are a common cause of rat infestation of the whole building. ”

“ Most rat infestation around poultry plants is due to the presence of numerous shelters and suitable breeding places. Three things are particularly to be avoided: Wooden floors on or within a few inches of the ground; double walls; and nest boxes, feed hoppers, and other fixtures placed so as to provide shelter for rats under or behind them. From a rat-proofing standpoint the floors as well as the foundation should be made of concrete. ”

“ Buildings that have neither basements nor continuous masonry foundations present more difficult rat-proofing problems. The most effective procedure is to construct a concrete foundation wall between the existing supports and, after the wall has hardened, remove the supports, if of wood, and replace them with concrete to make the wall continuous. ”

“ The rat proofing of granaries is of great importance, because of the abundance of food stored there and the corresponding opportunity for serious loss. The granary with concrete foundation and floors, tight-fitting doors, and screened ventilators presents no unusual problem, except possibly in connection with the elevator pit, which should be carefully checked against possible means of ingress for rats. Small wooden and portable granaries should be protected with wire netting. ”

“ Foundation walls should project a foot or more above the ground in order to protect the wooden parts of the building, and this also lessens the opportunity for rats to gnaw through the wall. A rat is not likely to cling to the exposed exterior of a building a foot above the ground while it gnaws a hole through wooden sheathing or siding. ”

“ Most new city buildings are now built practically rat proof, or could be made so with only minor changes in the plans and at small cost. Yet if certain essential details are not included at the start, endless rat troubles are likely to ensue. ”

“ All new buildings should be made rat proof. When plans are being drawn for a building, the rat problem is frequently overlooked, usually because rats are not often present near sites selected for new structures. ”