232 WASP STUDIES AFIELD 



baseball diamond, at first rather nervously with twitching 

 wings, then calmly as if her mind were all on her quiet home 

 duties. Then we saw that she was carrying little clods, 

 about as large as her head. It seemed that she was trying to 

 lay them on top of the hole, but they all went inside. She 

 did not, however, drop them in with a thump, but she went 

 in with them and came out at once in search of more. She 

 walked all the time (never flew), and seemed to become 

 more calm and serious as the work progressed. She walked 

 here and there, seizing every protuberance on the surface 

 of the hard-packed earth that might serve her, and giving 

 it a vigorous jerk to dislodge it. Presently she reversed her 

 action, took out the clods one by one and threw them away 

 until she had discarded seven clods of the size of her head ; 

 then she brought in their place one large clod which was 

 about twice the size of the first ones, and of precisely the size 

 needed. She laid it over the opening and brushed up a little 

 loose dirt oh, so nicely over and around it, and departed. 

 In taking her leave, she walked around the nest at first, then 

 circled around by short jumps gradually lengthening into 

 one-, two- and three-foot flights, then a continuous flight 

 in a wider circle, and away she soared to the weeds. We 

 can see no explanation of this juggling with the clods other 

 than that either this was her first nest, or she was not gifted 

 with the usual instinct or skill in judging exactly the right 

 size of clod, and she learned it only by experimenting. At a 

 later stage in the nest-building, clods are regularly taken 

 down into the burrow ; is it not possible that this female, who 

 was probably possessed of defective instinct in one phase 

 or another, had momentarily confused this temporary closing 

 with the permanent closing? 



After the caterpillar has been stored in the chamber at the 

 bottom of the burrow, a plug of clods is always placed in 

 the mouth of the chamber to prevent the dirt falling in 



