Part 2

Outside cellars frequently become infested with rats, and great havoc to stored produce almost invariably results. Considerable expense, if necessary, is justified in making the storage cellar rat proof. A cellarway with wooden steps and sills and earth floor is usually the source of the trouble. The sill soon rots or the rats burrow under it to gain entrance. The remedy is to construct a concrete floor and cellarway. This not only will exclude rats but will prove more economical in the long run. (Fig. 15.)

RAT PROOFING CITY BUILDINGS

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.

Large accumulations of trash usually, contain much waste food (fig. 16) and are certain to attract rats and furnish an ideal breeding place for them. Furthermore, they are a menace to health and should not be tolerated under any circumstances. All other rat harbors, such as wooden floors and sidewalks very near the ground, should be removed or replaced with concrete, and piles of lumber and various materials stored out of doors should be removed or elevated 18 or more inches. Particular care should be taken to see that sheds and other outbuildings, porches, steps, loading platforms, and similar structures on the premises are made rat proof, either by the use of concrete, by elevation, or by keeping them open to the light and easily accessible.

A thorough inspection should next be made of the building itself and careful note taken of alterations and repairs necessary for a thorough job of rat proofing. Inspection should begin in the basement. Doors and windows should fit snugly, particularly doors leading to outside stairs or elevators, and these should also be provided with automatic closing devices. Windows and ventilators should be screened or covered with gratings, the openings not more than half an inch square. Defects in basement floors should be repaired with concrete, and floor drains should be fitted with tight covers, (Fig. 17.)

Side walls should be carefully inspected, and all openings made for plumbing (fig. 18), electric-wire conduits, areas around windows and doors, and unpointed joints in masonry walls (frequently left when the exterior of the wall is hidden from public view by porches or platforms) should be carefully closed with cement mortar. (Fig. 19.)

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. The permanent closing of these spaces with noncombustible material not only shuts out the rats but also reduces the fire hazard by stopping the drafts and the rising of heated gases should a fire start in the basement. This process of blocking spaces between studs and furring is commonly known as fire stopping and is of such importance that the building regulations of many cities now require it. Figure 20 illustrates practical methods of rat proofing stud spaces in old buildings.

All openings between floors and in partitions made for the passage of pipes and wires and any defects in the wall should be closed with metal flashing. All dead spaces throughout the building, such as boxed-in plumbing, spaces behind or beneath built-in cabinets, counters, shelving, bins, show windows, and many similar places, should be removed, opened up, or effectively and permanently proofed against rats.

In the Southern States, where the roof rat occurs, similar care must be taken to make the upper floors and roofs of buildings rat proof, as this rat is an expert climber and frequently enters buildings by way of the roof. Doors at the top of stairs and elevators should fit snugly, and all ventilators, exhaust fans, unused chimney flues, and other openings should be screened. Broken skylights and openings under eaves and places where electric wires enter the building should be repaired or closed.

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. Where the cost prohibits following this plan and where the supporting sill and joists are at least 2 feet above the ground level, satisfactory rat proofing may be attained by stopping the spaces between the studs with weak concrete or other material resistant to rats for a distance of 8 inches above the floor level, or with galvanized-metal flashing nailed to the joists, plate, and floor. (Fig. 21.) The space beneath the building must be free from all rubbish and other material that would afford shelter for rats. A continuous masonry foundation, with screened openings to provide ventilation, presents a more pleasing appearance.

If the clearance between the ground level and the bottom of girders and joists is less than 2 feet, it may provide a hazardous rat harbor. One of three things should be done: The building should be elevated on piers 2 feet above the ground; a concrete foundation should be built as described above; or a continuous concrete curtain wall should be constructed under the entire outer wall of the building. (Fig. 22.)

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. It is therefore highly desirable that plans for every new building include specifications for rat proofing.

All new buildings in which foodstuffs are to be handled should have ground floors of concrete or other rat-proof material and concrete or masonry walls extending at least 2 feet below and 1 foot above the ground surface. All unnecessary openings in the foundation, walls, and floors should be permanently closed, and windows and ventilators should be screened. Stud spaces in frame construction should be stopped with noncombustible material resistant to rats. New buildings in which foodstuffs are not to be handled may, if desired, be elevated on piers or posts to provide a clearance of 2 feet between the ground level and the bottom of the supporting girders, although the concrete or masonry wall is more satisfactory.

MARKETS

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. . Here, more than anywhere else, the great need is the elimination of rat shelters, which in turn means the free use of concrete or other masonry. 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; and in such locations, with abundance of food at hand, rats are in the best possible position to thrive and multiply. The use of smooth concrete or tile counters (fig. 23) erected on concrete floors deprive rats of the essential shelter, provided that the space underneath the counter is kept clean and that stored material is moved frequently. The smooth surface also prevents the rats from climbing and makes it possible to leave edible products on the counter overnight without fear of their being damaged or contaminated by the rodents. If wooden floors are used, the boards should be laid flat on the concrete or on sleepers not more than half an inch high.

WAREHOUSES

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. Doors of warehouses frequently become jammed as a result of heavy trucking and should be carefully watched for defects that would admit rats. Concrete floors, in addition to being rat proof and fire proof, save labor because of the comparative ease with which loaded trucks can be rolled over them.

When warehouses are found to be seriously infested with rats, the trouble can usually be traced to such faulty construction as allows the rats access to spaces beneath floors or within walls, or even provides exits to near-by shelter outside.

Eats also gain entrance to rat-proofed warehouses through being shipped in with produce or when doors are left open, and once inside they may persist and do much damage from shelter afforded by piles of stored goods. Such damage, however, is usually small in comparison with that resulting from permanent rat harbors beneath floors, and the rats can be destroyed much more easily. A report from one flour warehouse indicated that it cost more than $3,000 a year to repair bags gnawed by rats and mice. 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. Bags of flour, grain, and other produce furnish harborage that can not well be avoided, but such goods are usually moved so frequently that rats do not have opportunity to

RAT PROOFING THE CITY

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. It has been demonstrated that such requirements not only are effective in reducing the numbers of rats to the minimum, but also that they greatly improve health conditions, reduce the fire hazard, and from a purely economic standpoint are profitable. 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.

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. 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 considering the suppression of rats, at the outset city authorities should discard all methods other than those that strike at the source of the trouble. The actual destruction of rats is necessary as a temporary means of stopping their depredations, but modern construction and sanitation are the weapons that must be relied upon to gain permanent relief. In addition to a rat-proofing ordinance, every city should have a law requiring that all garbage wherever accumulated be kept in rat-proof containers or garbage cans until collected or until destroyed by incineration or otherwise disposed of in a manner that would avoid the possibility of its providing food for rats. Containers should have covers not easily removed by dogs and other animals. The city should also enact regulations prohibiting the accumulation of trash, refuse, or waste matter of any kind on either public or private premises, and should provide adequate means for collecting and disposing of all waste.

Consideration should also be given to the sewer system. Although most modern sewers do not offer opportunity for the unrestricted breeding of rats, there are many still in use that furnish harbors for large numbers of these pests in sections of some cities. Of most importance is the corner catch basin, storm sewer, or street-drainage opening, which should be effectively remodeled, if necessary, to provide smooth interior vertical walls with a drop of at least 3 feet; rats are unable to jump 3 feet vertically or to climb smooth surfaces.

Another place that should receive attention is the city dumping ground, which frequently serves as an incubator for rats, and these soon overflow into near-by sections of the city. A study should be made of methods of disposing of waste materials and a system put into effect that will meet the requirements of the city and insure the destruction, removal, or adequate covering of all such food for rats. Any other conditions that may be found favorable for the breeding of rats, whether on public or on private property, should be declared a public nuisance and ordered corrected.

MODEL RAT-PROOFING ORDINANCES

The samples or models of rat-proofing and garbage-removal ordinances here given were prepared by the United States Public Health Service as a result of its experience in combating bubonic plague in several coastal cities. They have, in substance, been adopted and put into practice by a number of cities and have been found practicable. They should be applicable to any city after necessary allowance and possible changes have been made to conform to local conditions and constitutional considerations.

AN ORDINANCE DEFINING RAT PROOFING OF ALL BUILDINGS[3]

[3] U. S. Pub. Health Serv. Bul. 121, Preliminary Report on Proposed Antiplague Measures in Massachusetts.

Section 1. _Be it ordained, etc._, That it shall be unlawful for any person, firm, or corporation hereafter to construct any building, outhouse, or other superstructure, stable, lot, open area, or other premise, sidewalk, street, or alley, or to repair or remodel the same to an extent of -------- per cent of cost of construction within the city of --------, unless the same shall be rat proofed in the manner hereinafter provided for.

Sec. 2. _Be it further ordained, etc._, That for the purpose of rat proofing all buildings, outhouses, and other superstructures in the city of --------, except stables, shall be divided into two classes, to wit, class A and class B, and the same shall be rat proofed in the manner following, to wit:

_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; said floor shall extend and be hermetically sealed to walls surrounding said floor, which walls shall be made of rat-proof material or of concrete, stone, or brick laid in cement or mortar, and each wall shall be not less than 6 inches thick and shall extend into and below the surface of the surrounding ground at least 2 feet and shall extend not less than 1 foot above the surface of said floor; provided that wooden removable gratings may be laid on such concrete floors in such parts of such buildings, superstructures, and outhouses as are used exclusively as sales departments, provided that wooden flooring may be laid over the concrete wherever the intervening space between such flooring and the concrete shall not exceed one-half inch; provided further that any sleepers that are sunk into the concrete shall be creosoted.

_Class B._--All accidental and unnecessary spaces and holes, ventilators, and other openings other than doors and windows in every building, outhouse or other superstructure in the city of --------, shall be closed with cement, mortar, or other material impervious to rats or screened with wire having not more than one-half inch mesh, as the case may require, and all wall spaces shall be closed with cement, mortar, or other material impervious to rats, which closure shall extend the full thickness of the wall and shall extend upward at least twelve inches above the floor level, and the whole in such manner as to prevent the ingress or egress of rats; or the ingress or egress of rats from such double wall or space may be prevented by protecting the junction of said wall with the floor or other wall with metal flashing of galvanized iron of 28 or 30 gauge, provided that where such double wall is open beneath or is in communication with foundations of the house that said opening shall be effectively closed or said junction with foundations flashed with metal as provided above: _Provided_, That in all buildings, outhouses, and other superstructures of class A and in all stables where there are any spaces in walls between the wall proper and the covering on same, or in ceilings between the ceiling and floor, or other ceiling covering above, said spaces shall be eliminated by the removal of said covering, or so closed with cement, mortar or other material impervious to rats as to prevent the ingress or egress of rats: _Provided_, That all such wall spaces shall be closed with cement, mortar, or other material impervious to rats, which closure shall extend the full thickness of the wall and shall extend upward at least twelve inches above the floor level.

The cellar of every building hereafter erected within the building limits shall be made rat proof by the use of masonry or metal. All openings in foundations, cellars and basements In such buildings, except for doors and hatchways, and except also for such windows wholly above ground as may be exempted by the -------- in his discretion, shall be completely covered with screens of metal having meshes of not more than one-half of an inch in least dimension and constructed of rods or wire of not less than twelve gauge.