132 ANIMAL FORMS 



the rafters of barns and houses, we arrive at the social 

 wasps. As the name indicates, these insects, such as the 

 yellow-jackets and hornets, live together in companies 

 which consist, as in the ants and bees, of males, females, 

 and workers. They also are fond of the juices of fruits, 

 and many of them destroy insects which may be fed to the 

 young. Their nests are variously situated and constructed, 

 but all of them agree in being composed, at least in part, of 

 a grayish substance which is in reality a kind of paper. 

 With their jaws they scrape off from old logs and fences 

 small particles of wood, which they probably mix with saliva, 

 and rolling the mass into a ball set out for home. These 

 pellets are then flattened out into thin sheets, and worked 

 up into hexagonal cells, in which the eggs are laid. 



Along with the nests of the mud-daubers one frequently 

 notices the nests of some of the familiar wasps (Polistes), 

 which build cake-like nests composed of thirty or forty, 

 hexagonal cells attached by a stalk. Somewhat similar 

 nests, though usually more extensive, are constructed by 

 the yellow-jackets in cavities in the ground. The numer- 

 ous combs of the hornet are surrounded by several sheets of 

 wood-pulp, and the whole structure is attached generally 

 to the limb of a tree. 



In the spring the nests of all these species of wasps are 

 commenced by a single female, who has lived in a dormant 

 condition through the winter. She builds a small nest and 

 in time is surrounded by numerous workers, which live in 

 perfect harmony, enlarging the nest and rearing the young. 

 As autumn approaches the young males and females leave 

 the nest ; but the males, together with the workers, all suc- 

 cumb to the cold, and none but the females persist to found 

 a new colony the following spring. 



