SOME SOCIAL WASPS 293 



When they departed, we could see clearly that they never 

 carried away any pulp. They spent their time with their 

 heads buried in the rotted wood, with their abdomens pul- 

 sating in and out, which movement in the wasp generally 

 denotes contentment. We thought that they might be 

 merely seeking moisture, so we placed near them a piece 

 of juicy peach, from our lunch. This they stolidly ignored, 

 however, although they seemed to be aware of it and even 

 climbed over it on their way to the much preferred rotten 

 pulp. Hence we again concluded that instead of gathering 

 the wood-pulp for the construction of their nests, they were 

 merely enjoying their own repast. 



They are not always vegetable-feeders, however. On a 

 nest hung above the laboratory door, one worker brought in 

 a caterpillar. A second immediately cooperated with the 

 first, and together they soon divided it into two equal parts ; 

 then each took his portion and complacently chewed it 

 to pulp. 



We have previously recorded 16 how, when one comes 

 upon a Polistes nest at night, one finds the inhabitants 

 quietly at rest, their bodies and legs spread flat against the 

 under surface of the nest. They seem to be fully asleep, 

 for one may hold a strong light near them for several min- 

 utes before they show the slightest response. Early last 

 year, when the queens were nesting alone, we wondered 

 what became of them at night. It seemed that they went 

 elsewhere to sleep, until a careful examination of fifteen 

 nests of P. pallipes revealed them in hiding during the 

 night on top of the nest, and completely invisible from be- 

 low. There they clung to the stem of the nest, between 

 their roof and the ceiling of the barn. This condition was 

 constant for all the queens at that stage of nidification, and 



16 Ann. Ent. Soc. Amer. 9: 241. 1916. 



