28 INSECT BEHAVIOR 



in the house with great care and deliberation. Like so many newly 

 married couples, filled with the enthusiasm of a novel project, they 

 roamed about among the improved property that Kalacoon offered. 

 To facilitate my studies of their life history, I placed several pieces 

 of glass tubing, three or four inches long and a quarter of an inch 

 in diameter, about the laboratory. I inserted the tubes, which were 

 closed at one end, into pasteboard boxes, leaving the open end of 

 each projecting, so that the entrances were in plain view, but the 

 main part of the passages were quite dark, within the boxes. Thus I 

 made conditions in the tubes exactly like those in the reeds that the 

 insects naturally chose for their nests. 



They were an instant success, and within an hour or two, all were 

 occupied by enthusiastic couples. In the glass nests, I could watch 

 everything that went on. All that was necessary for me to do in 

 order to observe the occupants' behavior," was to remove the box 

 covers, and replace them when I had finished. 



True to the tradition of wasp history, the female proceeds with 

 the hard labor of nest building and providing for her family. The 

 male, while he never actually takes part in the work, sits menacingly 

 in the entrance, during his mate's absence, guarding the nest from 

 intruders of the same species that are ever-ready unbidden to acquire 

 a partly prepared home. He shows great interest in the work, fol- 

 lowing the female into the tunnel, watching closely whatever she may 

 be doing and squeaking continually in a high pitched key by vibrating 

 his wings. This is a common habit among many wasps during work 

 hours, but the species in question emits this strange little rasping 

 sound during almost all of its occupations. I interpret it as an 

 expression of pleasure or well-being, like a man who whistles at his 

 job. The sound is never heard during fright or anger, but of this 

 I shall treat in another chapter. 



Upon occupying a tube, the female's first procedure is to place 



