62 



RODENTS OF IOWA 



houses, and other places where such materials accumulate is also 

 an important factor in rat repression. Wastes, of whatever kind, 

 should be collected in metal containers furnished with covers, care 

 being taken that the covers are always in place. Such containers 

 should be emptied frequently and the contents utilized in some use- 

 ful manner or promptly burned. 



Control Measures. Mice are more easily trappM than rats; but 

 with either animal it is difficult to obtain results if food is plenti- 

 ful. Rats are also more cunning- and suspicious than mice and this 

 'fact contributes further to the difficulty of this method of control. 

 However, constant, consistent and concerted effort in trapping is 

 one of the best means of controlling the pests. 



One of the most efficient traps is the so-called "guillotine" trap 



I<IG. 13. Guillotine trap made entirely of metal. (From U. S. Department of 

 Agriculture, Bureau of Biological Survey.) 



made in various styles and sizes, those of simple construction being 

 preferable. Traps composed entirely of metal are best. In choos- 

 ing a bait it is best to select some food which is not found in the 

 vicinity. The following baits have been found excellent: Bacon, 

 wienerwurst, oatmeal, toasted cheese, and bread (with butter), fish, 



