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. (Fig. 1.) Raised platforms, 18 or more
inches high, should be provided upon which to pile lumber or other
materials that if placed on the ground would afford shelter for rats.
(Fig. 2.)
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.
Stone walls at times furnish excellent harborage for rats but, like the
woodpile, only if there is ample food near by. Stone walls supporting
embankments and driveways on sloping farmsteads are most frequently
infested, and when this occurs the inviting openings can usually be
readily closed with small stones and cement.
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.
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. 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. It would do so very quickly, however, if
such siding extended to the ground, where its work could be under cover
of vegetation or behind some object, particularly when the siding
becomes somewhat rotted, as would soon happen were it close to the
ground.
[Illustration: B3139M
Figure 2.--Lumber and other stored materials piled well off the ground
to prevent rat harborage]
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. Other approved building practices,
such as fire stopping double walls, eliminating waste dead spaces,
making doors, windows, and ventilators fit tightly, and screening or
permanently stopping all openings, are also necessary in rat proofing.
For simple farm buildings the foundation illustrated in Figure 3 meets
all the requirements of good construction and will keep the rats out if
the walls are tight.