B3137BM
Figure 23.—Rat proof market stalls. Rats are unable to climb the smooth tiles to get at foodstuffs left on the counter
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