218 WASP STUDIES AFIELD 



stems. She came out head first and carried in, one at a time, 

 three clods of earth; these we suppose she arranged to form 

 a plug in the angle of the "L"-shaped nest. After that, for 

 a few seconds, she kicked loose dust into the burrow. She 

 also kicked a straw, six inches in length, over the hole ; this 

 she carried a few inches away, and later, when it got in 

 her way a second time, she carried it in her mandibles and 

 flew with it for some distance and cast it away. She kicked 

 in more loose earth, and after each portion, went in to ram 

 or pack it down, humming in a discontinuous way that is, 

 it sounded as if with each ram of her head she notified us 

 with a sharp buzz of like duration. 



Thus she used all the loose dirt that lay near at hand ; the 

 region was hard and clean. There was yet about one-fourth 

 inch of the burrow to be filled, when she came with a hard 

 clod about five times as large as her own head, threw it into 

 the hole and went in herself as far as possible. We thought 

 this would be an easy way to fill up the burrow, and were 

 surprised to see her grasp it in her mandibles and continu- 

 ously, for three minutes, press down the earth in the depres- 

 sion with this tool, rubbing with it in a circular motion. 

 But our surprise was greater when we saw her throw out 

 this hard clod when she had tamped the dirt down suffi- 

 ciently; the easy way of filling a hole was not her way. A 

 much smaller clod was then thrown in and beaten to dust 

 with her head and face. This was plainly to be seen, and 

 this later clod must have been intended for this purpose since 

 the mandibles and head were used to break it up, and no 

 attempt was made to swing it in a circular motion. It is 

 quite likely that this small one could also have served as a 

 tool if she had wanted to use it to that purpose, and we feel 

 sure also that the former one could have been bitten and 

 pounded to pieces with her stout mandibles, had she wished 

 to do so. But she had done the necessary pounding; filler 



