90 RODENTS OF IOWA 



extend out for considerable distances into such pastures and or- 

 chards. Their food consists largely of roots of grasses and various 

 cultivated small grains, and in late fall and winter they do Con- 

 siderable damage to the roots of fruit trees and nursery stock. In 

 this latter respect this form probably causes greater damage than 

 does the common meadow mouse. In autumn prairie mice are often 

 to be found under corn shocks where they cause considerable loss of 

 grain. If cultivated crops are not to be had, these mice feed upon 

 the roots, seeds, and leaves of various wild plants. 



The nest resembles that of the meadow mouse in its construction 

 and situation, but is somewhat smaller, while the trails and run- 

 ways are constructed much as described for that species. Prairie 

 mice seem to multiply less rapidly than meadow mice, since the 

 number produced in a litter is usually but three or four and the 

 long droughts of summer and continued extreme cold of winter 

 lessen the reproductive period. 



Following is an extract from Robert Kennicott's account of the 

 habits of the prairie mouse in Illinois: "Their winter burrows on 

 the uncultivated prairie are often in old ant-hills, or, if not, the 

 earth thrown out of them forms little hillocks. They are not very 

 deep, seldom over six inches or a foot, but are remarkable for the 

 numerous and complicated chambers and side-passages of which 

 they are composed. In one of these chambers, considerably en- 

 larged, is placed the nest, formed of fine, dry e;rass. It is globular, 

 from four to six inches in diameter, and with but a small cavity 

 in the centre, which is entered by a very narrow opening on one 

 side. This burrow and nest are occupied in winter, and in ?.t at 

 least the first litter of young is produced in the spring; but in 

 the summer and fall these meadow-mice may be found in similar 

 nests in grass, above ground, in which the young are often, if not 

 usually brought forth. Nests formed under the snow in winter are 

 also occupied by them. From the burrows, innumerable runways 

 traverse the neighborhood, intersecting those from other burrows, 

 thus forming a complete net-work so that often scarcely a square 

 yard can be found in an acre not crossed by one or more of these 

 tracks. The runways of one pair may sometimes be traced five 

 or ten rods on every side. These roads are not only formed for use 

 in winter, when the ground is covered with snow, but are also em- 

 ployed as highways in summer. They are made above ground by 

 pressing down and gnawing off the grass, and the earth is often 



