CHECKS UPON INCREASE OF USEFUL BIRDS. 365 



before their eyes were opened, and while they were still 

 taking their mother's milk, and could never have tasted 

 birds or eggs. They were afterwards given to Mr. C. Allan 

 Lyford, and reared in a cage at Worcester. One day, when 

 they were well grown, one was given its liberty. The first 

 thing it did was to climb an apple tree, go to a Eobin's 

 nest, and begin eating-out the brains of a young bird. How- 

 ever, its eagerness for fresh meat may have been caused by 

 a lack of animal food in its cage diet. This habit of killing 

 young birds has been reported from several counties in the 

 State, and must be widespread. Squirrels are quite car- 

 nivorous. When meat is put up on trees for birds, squirrels 

 frequently come and eat it ; also, they are destructive to 

 apples, pears, cherries, strawberries, and sometimes even to 

 grapes, and they dig up seed corn in planting time ; but 

 they have two good habits, — they plant trees and they eat 

 insects. Once in summer, when there were no nuts, acorns, 

 or buds for squirrels to eat, I saw a gray squirrel in the 

 woods go over a black oak about fifty feet in height, search- 

 ing systematically, branch by branch, with its nose close to 

 the bark, and apparently catching about all the insects rest- 

 ing there. It went to a brown-tail moth web, and spent some 

 time there. I distinctly saw one caterpillar in its mouth. 

 The tree had been considerably infested by leaf hoppers and 

 caterpillars. As it had a small top, and could easily be ex- 

 amined, I climbed and inspected it after the squirrel had 

 gone. My search occupied about half an hour. The smooth, 

 clean bark formed a dark, glossy background, on which in- 

 sects could plainly be seen, and the foliage was thin, and 

 not hard to examine ; but I could find only about a dozen 

 insects, and no brown-tail caterpillars. Since then I have 

 observed other similar cases. It is not so widely known that 

 squirrels eat insects as that they rob birds' nests. Possibly 

 their virtues may balance their faults ; but we shall never be 

 able to determine their economic position until a thorough 

 study of their food habits can be made. 



