THE WHITE-FOOTED MOUSE. 325 



To recapitulate : judging from the number of nests examined — of 

 course, another such series might give different results — the winter 

 retreats or bush-nests of the white-footed mice are usually modified 

 birds' nests ; but in some cases the modification appears to be ex- 

 tended to practically a new construction. 



Once within their nests, the white-footed mice are not readily dis- 

 turbed during the day ; and, unless the smilax or other growth is 

 greatly agitated, they will not even take the trouble to look about 

 them. By gently cutting my way toward the nest with a pair of 

 shears, snipping here and there a branch or two, and drawing others 

 gently aside, I have never failed to successfully surprise the timid 

 occupants in their snug retreats. It is fairly safe, therefore, to con- 

 clude that I procured a pretty accurate knowledge of the number of 

 occupants of each nest, the relative proportion of the one to the other 

 sex, and of old and young. Thirty-six nests contained each a female 

 mouse, and of these twenty-two were associated with young able to 

 walk, while the others were burdened with the care of helpless offspring 

 but a few days old. In not a single instance did I find a male mouse 

 in these nests, while in the six other nests each was found to contain 

 a single adult male mouse and no other occupant. 



This unsocial condition of affairs seems to me the more strange, as 

 in several nests placed upon the ground — many such nests are occupied 

 the year round — both parents were found. They were not accom- 

 panied by any offspring, however ; and it would seem as though a 

 separation took place on the birth of a litter. Such facts tempt one 

 to theorize, but I desist. 



It was a pretty sight to see the mice when forced to quit their airy 

 quarters in a thicket of smilax. Be the vine ever so slender, they took 

 no uncertain steps, but tripped lightly down from point to point, and 

 never arriving at a confusing corner. One female mouse turned just 

 twenty times before she reached the ground. Once there, although 

 she had proceeded very cautiously before, she suddenly disappeared. 

 This, indeed, is always the case ; but just where they go when they 

 reach terra firma remains to be shown. 



The prevalent impression is that every mouse has a subterranean 

 retreat directly beneath the nest in the bushes, and passes from one 

 to the other as fancy dictates. Their actions seem to bear out the 

 truth of this, but I have never been able to discover such underground 

 retreats in positions that conclusively showed they were frequently 

 visited by the bush-dwelling mice above them. On the other hand, I 

 have found the evicted mice to take shelter under dead leaves, pieces 

 of bark, or limbs of trees. If disturbed from such lurking-places, they 

 very seldom attempt to re-enter the elevated bush-nests, but scamper 

 off over the weedy, leaf-strewed meadow. 



Besides reconstructing nests of birds as dwellings for themselves, 

 they convert others into magazines stored with carefully selected 



