64 



RODENTS OF IOWA 



with a stick or other instrument. Sometimes also gloves are worn 

 in the setting of these traps. 



The common spring steel trap (No. or 1) may be used, but since 

 the rat is usually caught by the foot its squeals frighten the other 

 rats and they are made more wary. Such traps may be set in nar- 

 row runways or at the openings of burrows and covered lightly by 

 oats or other grain. Care should be taken to keep the trigger plate 

 free from grain. A food which is not commonly accessible will 

 prove to be the best bait ; so that in and around a slaughter house 

 or meat market, vegetables or grain will serve best, while in a barn 

 or granary a bait of meat will give best results. The bait should 

 be kept fresh, should be handled as little as possible, and should 

 be changed when a given kind no longer .continues attractive. Of 

 course other foods should be made as inaccessible as possible while 

 trapping is in progress. 



The barrel trap is reported, to have been used with considerable 

 success in some places and the method of using it may be briefly 

 mentioned. The rats are first attracted to a given place for several 

 nights by baits placed upon the tops of barrels covered with heavy 

 brown paper or with a light wooden top. After the rats become 

 accustomed to this method of feeding a cross is cut in the paper 



FIG. 15. Barrel trap; 1, with stiff paper cover; 2, with hinged cover; a, stop; 

 6, baits. (From U. S. Department of Agriculture, Bureau of Biological 

 Survey. ) 



and the rats on coming to the usual place fall into the barrel. In 

 the case of the wooden-topped barrel, the cover is hinged on a rod ; 

 and the baits are fastened to the cover which is properly weighted 

 so that it will turn with the weight of the rat, and after the animal 

 has been dropped into the barrel will again come to a horizontal 

 position ready for the next victim. A stop is placed on the side 



