House Rats and Mice Farmers' Bulletin 896   By: David E. Lantz

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HOUSE RATS AND MICE

DAVID E. LANTZ

Assistant Biologist

[Illustration]

FARMERS' BULLETIN 896

UNITED STATES DEPARTMENT OF AGRICULTURE

Contribution from the Bureau of Biological Survey

E. W. NELSON, Chief

Washington, D. C. October, 1917

Show this bulletin to a neighbor. Additional copies may be obtained free from the Division of Publications, United States Department of Agriculture

WASHINGTON: GOVERNMENT PRINTING OFFICE: 1917

The rat is the worst animal pest in the world.

From its home among filth it visits dwellings and storerooms to pollute and destroy human food.

It carries bubonic plague and many other diseases fatal to man and has been responsible for more untimely deaths among human beings than all the wars of history.

In the United States rats and mice each year destroy crops and other property valued at over $200,000,000.

This destruction is equivalent to the gross earnings of an army of over 200,000 men.

On many a farm, if the grain eaten and wasted by rats and mice could be sold, the proceeds would more than pay all the farmer's taxes.

The common brown rat breeds 6 to 10 times a year and produces an average of 10 young at a litter. Young females breed when only three or four months old.

At this rate a pair of rats, breeding uninterruptedly and without deaths, would at the end of three years (18 generations) be increased to 359,709,482 individuals.

For centuries the world has been fighting rats without organization and at the same time has been feeding them and building for them fortresses for concealment. If we are to fight them on equal terms we must deny them food and hiding places. We must organize and unite to rid communities of these pests. The time to begin is now.

HOUSE RATS AND MICE.

CONTENTS.

Page.

Destructive habits 3

Protection of food and other stores 5 Rat proof building 5 Keeping food from rats and mice 9

Destroying rats and mice 11 Traps 11 Poisons 15 Domestic animals 18 Fumigation 18 Rat viruses 19 Natural enemies 20

Organized efforts to destroy rats 20 Community efforts 21 State and national aid 21

Important repressive measures 23

DESTRUCTIVE HABITS OF HOUSE RATS AND MICE.

Losses from depredations of house rats amount to many millions of dollars yearly to more, in fact, than those from all other injurious mammals combined. The common house mouse[1] and the brown rat[2] (fig. 1), too familiar to need description, are pests in nearly all parts of the country; while two other kinds of house rats, known as the black rat[3] and the roof rat,[4] are found within our borders.

[Illustration: FIG. 1. Brown rat.]