Among domestic animals employed to kill rats are the dog, the cat, and
the ferret.
=Dogs.=--The value of dogs as ratters can not be appreciated by persons
who have had no experience with a trained animal. The ordinary cur and
the larger breeds of dogs seldom develop the necessary qualities for
ratters. Small Irish, Scotch, and fox terriers, when properly trained,
are superior to other breeds and under favorable circumstances may be
relied upon to keep the farm premises reasonably free from rats.
=Cats.=--However valuable cats may be as mousers, few learn to catch
rats. The ordinary house cat is too well fed and consequently too lazy
to undertake the capture of an animal as formidable as the brown rat.
Birds and mice are much more to its liking. Cats that are fearless of
rats, however, and have learned to hunt and destroy them are often very
useful about stables and warehouses. They should be lightly fed, chiefly
on milk. A little sulphur in the milk at intervals is a corrective
against the bad effects of a constant rat or mouse diet. Cats often die
from eating these rodents.
=Ferrets.=--Tame ferrets, like weasels, are inveterate foes of rats, and
can follow the rodents into their retreats. Under favorable
circumstances they are useful aids to the rat catcher, but their value
is greatly overestimated. For effective work they require experienced
handling and the additional services of a dog or two. Dogs and ferrets
must be thoroughly accustomed to each other, and the former must be
quiet and steady instead of noisy and excitable. The ferret is used only
to bolt the rats, which are killed by the dogs. If unmuzzled ferrets are
sent into rat retreats, they are apt to make a kill and then lie up
after sucking the blood of their victim. Sometimes they remain for hours
in the burrows or escape by other exits and are lost. There is danger
that these lost ferrets may adapt themselves to wild conditions and
become a pest by preying upon poultry and birds.