ANIMAL COMMUNITIES AND SOCIAL LIFE 161 



Q 



ing from the main or public entrance burrow. As a well- 

 known entomologist has said, Andrena builds villages com- 

 posed of individual homes, while Halictus makes cities 

 composed of apartment houses. The bumble-bee (Fig. 96), 

 however, establishes a real community with a truly com- 

 munal life, although a very simple one. The few bumble- 

 bees which we see in winter time are queens; all other 

 bumble-bees die in the autumn. In the spring a queen 

 selects some deserted nest of a field-mouse, or a hole in 

 the ground, gathers pollen which she molds into a rather 

 large irregular mass and puts into 

 the hole, and lays a few eggs on the 

 pollen mass. The young grubs or 

 larvee which soon hatch feed on the 

 pollen, grow, pupate, and issue as 

 workers winged bees a little small- 

 er than the queen. These workers 

 bring more pollen, enlarge the nest, 

 and make irregular cells in the pol- 

 len mass, in each of which the queen 

 lays an egg. She gathers no more 

 pollen, does no more work except 

 that of egg-laying. From these new 

 eggs are produced more workers, and 

 so on until the community may come 

 to be pretty large. Later in the sum- 

 mer males and females are produced 

 and mate. With the approach of 

 winter all the workers and males die, 

 leaving only the fertilized females, 

 the queens, to live through the win- 

 ter and found new communities in 

 the spring. 



The social wasps show a communal life like that of the 

 bumble-bees. The only yellow-jackets and hornets that 

 live through the winter are fertilized females or queens. 

 12 



FIG. 96. Bumble-bees, a, 

 worker ; 6, queen or fer- 

 tile female. 



