HOME LIFE OF BIRDS 37 



almost exclusively on insects. The most common 

 kinds of food are caterpillars, spiders, and grass- 

 hoppers. Some birds feed fruit to their young, the 

 kingfishers feed fish, and hawks and owls feed mice 

 and other rodents. 



Large insects are frequently broken into smaller 

 pieces by the parents before being fed to the young. 

 Some birds, like the hummingbird and flicker, feed 

 their young by regurgitation. The food is first par- 

 tially digested in the crop or stomach of the parent 

 bird and then fed to the young by the parent bird's 

 inserting its bill far into the mouth of the nestling. 

 As a prevention against overfeeding, young birds 

 have an instinctive- response in the throat. The 

 parents place the food in the throat, and if the 

 gullet is already full, the throat does not respond, 

 and the parent removes the food and puts it into 

 the throat of another, till one is found which does 

 respond. 



Cleaning the nest. Another duty of the parents is 

 to keep the nest clean. The excreta of the young are 

 voided in membranous sacs, and these are either 

 removed by the parent or swallowed. 



Brooding. During hot days birds may frequently 

 be seen brooding their young. They stand with 

 spreading wings and tail shielding the young from 

 the sun's rays, often themselves panting with wide- 

 opened bills. During hot days this may occupy a 

 large portion of the bird's time, the bird sometimes 



