COMMON MAMMALS OK WKSTKHN MONTANA. 



on pages •_".», after 1 1 it* treatment with arsenic-coated dandelion 

 and clover heads not a single rat could he found. Although this is 

 (he only time the author has tried arsenic as a wood-rat poison, he 

 believes that this inexpensive preparation will prove effective against 

 the animals. Wood rats are easily caught in ordinary rat traps haited 

 with prunes, raisins, or oatmeal. 



MEADOW MICE. 



DISTRIBUTION AND HABITS. 



Three kinds of meadow mice occur in the valleys of western Mon- 

 tana, and another lives high up in the mountains; hut since all three 

 of the valley species may sometimes he found in the same hayfield, 



Fig. 23. — Meadow mouse caught in unbailed trap. 



and since their habits are much alike, it is unnecessary here to dis- 

 tinguish between them. (Fig. 23.) 



As a rule these mice occur only in damp fields and meadows where 

 there is an abundance of grass. In such jolaces their runways form 

 networks on the surface of the ground, with occasional burrows lead- 

 ing to underground passages. Their nests are compact masses of 

 dry glass, usually placed in rank vegetation or under fallen logs. 

 Sometimes, however, the mice live underground, often among the 

 loots of rotten stumps. (Figs. 24 and 25.) Several litters of young 

 are born each year, the average number in a litter being six. 



INJURY TO CROPS. 



Under normal conditions meadow mice in hayfields do not very 

 seriously injure the crop: but their nests are a continual source of an- 



484 



