122 WILD NEIGHBORS CHAP. 



birds, and reptiles, without whose assistance we 

 should be unable to endure their hordes, while 

 the results of their pernicious activity are con- 

 stantly apparent. Read this extract from Kenni- 

 cott's masterly but nearly forgotten papers on the 

 mammals of Illinois, and note how important a 

 factor in the relations of men and animals are 

 these unseen foes : he is speaking more particu- 

 larly of the true meadow-mice of the genus Arvi- 

 cola, but we may take his statements as good for 

 the whole class. 



"The food and general habits of the different 

 species are much alike, though some prefer high, 

 and others wet ground ; while others inhabit the 

 woods, prairies, etc. All the species burrow, and 

 none climb trees. The common food of those I 

 have observed is the grasses and other herbaceous 

 plants, their seeds and roots, and the seeds and 

 acorns, as well as the bark, of trees in the woods, 

 with grain and vegetables, when inhabiting culti- 

 vated fields. Some are omnivorous, as has been 

 observed in their habits while in captivity. To 

 what extent they eat animal food when at liberty, 

 I am unable to say, though it is probable that 

 they consume some insects in summer ; and they 

 may even obtain a few, with the pupae and eggs 

 of more, concealed in the grass traversed by them 

 in winter. Some kinds, at least, lay up stores of 

 food for winter. All are active at this time, mov- 

 ing about in the coldest weather, and never hiber- 

 nate like marmots. 



"One characteristic, certainly possessed by all 

 the species in common, is their ability to destroy 



