struction of rats, elimination of 

 rat harborages, elimination of 

 food supply for rats, and rat- 

 proofing of buildings. Further- 

 more, such a program should re- 

 ceive attention at all times of the 

 year. Once initial success has 

 been attained, maintenance is es- 

 sential, or conditions will soon 

 revert to their former status. A 

 constant watch must be main- 

 tained to repel new invaders as 

 quickly as they appear. Complete 

 and wholehearted cooperation of 

 all concerned, public and private, 

 is the keystone to a successful 

 program. 



USE OF POISONS 



The most efficient means of ef- 

 fecting wholesale destruction of 

 rats is the use of poisons, or ro- 

 denticides, as they are called. 

 Poisons that are deadly for one 

 warm-blooded animal, however, 

 are also more or less poisonous to 

 others. Human beings, pets, and 

 domestic animals must be pro- 

 tected against accidental poison- 

 ing. Care must be observed in 

 handling the materials and every 

 precaution taken to avoid contam- 

 inating foodstuffs. The poison 

 that best fits the conditions under 

 which it is to be used should be 

 chosen. 



POISONS FOR GENERAL USE 



For general use those poisons 

 should be selected that can be used 

 by the average person without 

 difficulty, providing instructions 

 are followed and proper precau- 

 tions taken at all times. These 

 include red squill, ANTU, and 

 zinc phosphide. 



Red Squill 



Red squill is obtained from the 

 bulb of a lily-like plant that grows 

 in the Mediterranean region. It 

 has the peculiar advantage over 



other poisons of containing an 

 emetic agent that causes vomiting 

 in most animals other than rats 

 and thereby the poison is elimi- 

 nated. Furthermore, it has a 

 disagreeable taste, so that many 

 animals will not touch it. ISTever- 

 theless, it is a poison and should 

 be treated as such. 



Red squill, as imported, lacks 

 uniform toxicity and often may 

 prove to be an unreliable rat 

 poison unless it has been brought 

 up to uniform strength by an 

 extraction process. Purchasers 

 should insist upon obtaining red 

 squill that has a guaranteed mini- 

 mum toxicity not to exceed 500 

 mg/kg (500 milligrams of the 

 toxic element to a kilogram of 

 body weight of the rat). The 

 most satisfactory results are ob- 

 tained when the poison is mixed 

 with the bait material in the pro- 

 portion of one to nine ; that is, the 

 resulting mixture should contain 

 10 percent red squill. When dry 

 cereal is used as the base, the red 

 squill should be added to the 

 dry ingredients and the mixture 

 stirred thoroughly before water 

 is added. When meat or fish is 

 used, a thin paste of red squill and 

 water is> prepared, care being 

 taken to avoid lumping, and this 

 is then blended with the bait 

 material. 



ANTU 



ANTU is the abbreviated name 

 for the chemical alphanaphthyl- 

 thiourea, which is highly toxic to 

 the common brown, or Norway, 

 rat, but much less so to the black 

 and other forms of climbing rats. 

 For this reason ANTU is not rec- 

 ommended for general use in 

 areas in which the climbing rats 

 predominate, as in the Southern 

 States. ANTU is a grayish- 

 white powder, insoluble in water, 

 chemically stable, and nonirritat- 

 ing to the skin of human beings. 

 It kills rats by causing an accu- 



