Page:Popular Science Monthly Volume 91.djvu/933

This page needs to be proofread.


Popular Science Monthly

��year, and that on a farm at least 50 cents more was wasted; he believed that in a city the damage is greater. Hotel managers and restau- rant keepers put the cost of keeping a rat at $5 a year or even higher.

These figures were reason- able before the war sent prices soaring. Now they are far too low.

The Rat Is an International Problem

It would be tedious to enumerate the different ways in which rats cause direct or indirect loss. Some of them are injury to furniture and clothing, destruction of valuable papers, stripping labels from canned goods, hiding jewelry, destruction of poultry, and the catching and destruction of hatchings in fisheries. They even gnaw into the hoofs of horses until the feet bleed, and .have been known to kill young pigs and lambs. The variety of articles carried away for nest building is shown by a nest in which were found bits from three bedroom towels, two table napkins, five dust 'cloths, two pairs of knick-

���At left is the brown rat, at right the black rat, each one- third its size

��917

erbockers, six linen hand- kerchiefs, and one silk hand- kerchief. Near the same nest were stored one and a half pounds of sugar, a pudding, a stalk of celery, a beet, carrots, turnips, and potatoes.

Another count against the rat is the spreading of disease germs. The bubonic plague is spread almost entirely by a rat- borne flea. Trichinosis is also spread by rats. As the rodents are frequenters of drains, pi iv- ies, and sewers in their search for food, they spread ptomaines. In slums, where they are present in large numbers, they are a factor in spreading highly contagious and malignant diseases. Owing to their prevalence on ships, they carry disease from seaport to seaport, and are a menace to be considered in the international control of the world's plagues.

The rat that is most common and most troublesome in the United States is the brown rat. The black rat, formerly abundant in the eastern part of the coun- try, is now rare in the United States; it was introduced earlier than the brown rat, but seems to be unable to hold its own here suc- cessfully.

At left: A single corn stalk showing how com- pletely the rats stripped the corn-cobs of grain

���An entire cornfield devastated by rats, which climbed the stalks, tore off the husks and ate the grain, leaving only the cobs

��The carcass of a young Canada goose, killed like hundreds of others by a rat which gnawed off the head and drank the blood

�� �