A BIRD'S NEST, AND OTHER ANIMAL HOMES 



37 



munities, and similarly only a few kinds of wasps. All 

 the ants, however, and more than 2000 living species of 

 them are known, have a communal life. But the solitary 



Fig. 20. — An oak-gall (California) home of a small four-winged gall insect; 

 in upper figure the gall on oak-branch; in lower, the gall cut open to 

 show the inside. (Upper figure slightly reduced; lower figure, natural 

 size; from specimen.) 



bees and wasps give more or less special attention to 

 their young, all of them building homes for them, and 

 providing them with food either by storing it in a closed 

 nest and leaving the young to supply themselves from it, 

 or by leaving the nest open and bringing food daily after 



