420 CHAPTERS ON THE NATURAL HISTORY 



stantly feeding as they do upon small rodents of every descrip- 

 tion, the farmers' lands would literally be overrun with field mice, 

 and the raising of grain thus be rendered almost futile. It may 

 be said here, in fact, that the direst enemies the deer mice have 

 are hawks and owls, and these birds, especially at such times as 

 when rearing their young, capture and consume almost incredi- 

 ble numbers of them. Some snakes, weasels, and other animals 

 also prey upon Deer mice, but all of these put together by no man- 

 ner of means are as responsible for keeping their undue increase 

 in check as are certain hawks and owls. 



These Deer mice are chiefly nocturnal in habit, and are but 

 rarely seen by men during the daytime, unless special search is 

 made for them in their hiding places. In confinement they be- 

 come very gentle and tame, and I have seen it stated in various 

 popular works that when kept in cages they will at times sit upon 

 their haunches and give vent to certain low and peculiar singing 

 notes. This accomplishment has never been noticed in them by 

 the present writer, though I have known the female of the com- 

 mon House mouse thus to " sing " during the time she has been 

 giving birth to her litter. Upon one occasion I personally ob- 

 served a case of this kind, the very distinctly audible notes in- 

 citing me to make search in a drawer containing house linen. 

 Here, by cautious search, I discovered a female House mouse, 

 with two newly born young beneath her. Upon being exposed, 

 the " notes " ceased, and she ran in among the napkins and table 

 cloths. An hour or so later the " singing " again attracted my at- 

 tention, and upon going directly to the same spot, the mother 

 mouse was once more surprised, and this time her litter had been 

 increased by the addition of two or three more young ones. 



Deer mice, in common with their other near relatives, are ex- 

 tremely nervous creatures, and upon the occurence of sudden 

 sharp sounds in their immediate neighborhood, they will lay back 

 their ears, jump several inches off their feet, and at the same 

 time protruding their eyeballs, as if those organs were about to 

 pop clean out of their sockets. For short distances they can 

 swim well, but just so soon as the fur gets thoroughly wet, they 

 become exhausted and soon drown. When in the trees, Deer 

 mice are good leapers, and by this means make rapid progress in 

 passing among the smaller limbs and twigs. 



Notwithstanding the extreme abundance of these little ani- 

 mals, and the great length of time they have been known to us, 



