28o The Orders of Insects 



most of the genera are " solitary," that is they form no true social 

 communities, though the proximity of the nests of many pairs often 

 leads to large assemblies. The nests are formed in the earth, 

 hollowed out in wood, or constructed of hardened clay ; the usual 

 food of bees and their larvs is honey. Some genera are " unbidden 

 guests" in the nests of others, and the larvs of some live as actual 

 parasites on those of other bees. The higher bees form true social 

 communities consisting for the most part of undeveloped females or 

 "workers" (fig. 154). The cells of their nests are made of wax 

 (fig. 155) which is secreted by their abdominal glands; they collect 

 pollen from flowers in the cavities of their wide flattened hind-shins, 

 and suck honey by means of their grooved tongues. The Apids are 

 world-wide in their range (161-5). 



