Produced by Larry B. Harrison, Josephine Paolucci and the Online Distributed Proofreading Team at https://www.pgdp.net. Issued May 31, 1907. U. S. DEPARTMENT OF AGRICULTURE. FARMERS' BULLETIN 297. METHODS OF DESTROYING RATS. BY DAVID E. LANTZ, _Assistant, Bureau of Biological Survey_. [Illustration] WASHINGTON: GOVERNMENT PRINTING OFFICE. 1907. [Transcriber's Note: Words surrounded by tildes, like ~this~ signifies words in bold. Words surrounded by underscores, like _this_, signifies words in italics.] LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF BIOLOGICAL SURVEY, _Washington, D. C., May 15, 1901_. SIR: I have the honor to transmit herewith for publication Farmers' Bulletin No. 297, containing concise directions for the destruction of rats, prepared by David E. Lantz, an assistant in this Bureau. The damage done by these rodents, both in cities and in the country, is enormous, and the calls for practical methods of destroying them are correspondingly numerous and urgent. It is believed that by following the directions here given the numbers of this pest can be greatly reduced and the losses from them proportionally diminished. Respectfully, C. HART MERRIAM, _Chief, Biological Survey_. HON. JAMES WILSON, _Secretary of Agriculture_. CONTENTS. Page. Introduction 3 Methods of destroying rats 4 Poisoning 4 Trapping 5 Use of ferrets and dogs 6 Fumigation 7 Rat-proof construction 7 Natural enemies of rats 8 Conclusions 8 ILLUSTRATION. Page. FIG. 1.--Method of baiting guillotine trap 6 METHODS OF DESTROYING RATS. INTRODUCTION. The brown or Norway rat (_Mus norvegicus_) is the worst mammal pest in the United States, the losses from its depredations amounting to many millions of dollars yearly--to more, indeed, than the losses from all other injurious mammals combined.[A] In addition to its destructive habits, this rat is now known to be an active agent in disseminating infectious diseases, a fact which renders measures for its destruction doubly important. [Footnote A: Several species of rats are known as "house rats," including the black rat (_Mus rattus_), the roof rat (_Mus alexandrinus_), and the brown rat (_Mus norvegicus_). Of these, the last is the commonest and most widespread in this country. Not one of these species is a native, but all were imported from the Old World. As their habits in general are similar, the instructions given in the bulletin apply alike to all.]