ANIMAL COMMUNITIES AND SOCIAL LIFE 325 



She then waits in an upper cell of the nest until the young 

 bees issue from their cells, when she leads them off, and 

 each begins active life on its own account. The mining- 



FIG. 194. Nest of carpenter-bee. 



FIG. 195. Nest of Andrena, the mining-bee. 



bees (Andrena), which make little burrows (Fig. 195) in a 

 clay bank, live in large colonies that is, they make their 

 nest burrows close together in the same clay bank, but each 

 female makes her own burrow, lays her own eggs in it, fur- 

 nishes it with food a kind of paste of nectar and pollen 

 and takes no further care of her young. Nor has she at 

 any time any special interest in her neighbors. But with 

 the smaller mining-bees, belonging to the genus Halictus^ 

 several females unite in making a common burrow, after 

 which each female makes side passages of her own, extend- 



