72 



RODENTS OF IOWA 



bark of young fniit trees or nursery stock, but such harm is more 

 often due to meadow mice (Microtus)."^'^ 



This species often enters out-buildings and even houses, particu- 

 larly in rural districts and communities in which the house nuuse 

 has not become established, for the latter mouse seems able to drive 

 away the white-footed form. In such places this mouse finds a com- 

 fortable living and pleasant quarters, but commits more or less 



Fig. 17. — Field-Mouse skulls taken from pellets found under owl roost in Smith- 

 sonian tower, Washington, D. C. (From U. S. Department of Agricultuie, 

 Bureau of Biological Survey.) 



depredation in the way of cutting* up cloth for nesting materials and 

 destroying foodstuffs and provisions of various kinds. Sometimes 

 damage is done in granaries and in hay and straw stacks. Since 

 this mouse is so prolific, and since it is mainly nocturnal in its 

 habits, with the result that it is not much attacked by hawks, its 

 numbers in a given locality may increase considerably above normal 

 with resulting injury to agricultural interests. HoM'ever, in no case 

 has the writer heard specific charges of serious damage against tbe 

 northern white-footed mouse in the state, although it is probable 



"Lantz, D. E., N. A. Fauna No. 2S, 27, 1909. 



