THE SENSE OF DIRECTION IN WASPS. 217 



pleted, is most thorough, and, as a usual thing, when she first 

 comes out on each succeeding morning, she reviews the situa- 

 tion more or less carefully. Individuals differ in this respect, 

 however, some studying their local habitat much more than 

 others. In this as well as in all other matters our observations 

 are in complete accord with those of Sir John Lubbock who- 

 says: "Indeed, many of my experiences seem to show not 

 only a difference of character in the different species of ants,, 

 but that even within the limits of the same species there are in- 

 dividual differences between ants, just as between men."* 



Astata bicolor made her study in a different way from Sphex- 

 ichneumonea. She first flew from the nest to a spot near by and 

 settled there, returning, after a moment, to the nest, or else fly- 

 ing to another resting place. After pausing in a number of 

 places (in the case of the one followed in the diagram, thirteen),, 

 she finishes by a rapid zig-zag flight. (PI. XII., fig. 3.) An- 

 other wasp of this species, unicolor, differed from licolor in not 

 returning to the nest from the different resting places, and in 

 walking from one to another of them instead of flying, although 

 the last part of the study was made on the wing. (PI. IX., fig. 

 5, and PI. XII., fig. 4.) After we had excavated a unicolor 

 nest, the owner dug a second hole five inches away. At 

 eleven o'clock of the day on which this nest was completed she- 

 went away and was gone until fifteen minutes after one. Upon 

 her return she was much perplexed as to the situation of her 

 home, there evidently being some confusion in her mind be- 

 tween the old nest and the new one. At first she alighted upon 

 the first site and scratched away a little earth, and then explored 

 several other places, working about for twelve minutes, when 

 she at last found the right spot. 



Cerceris deserta was one of the wasps that objected strongly 

 to our presence, and she also made a great deal of fuss about 

 leaving her nest. Nearly all the species circle before leaving 

 a spot to which they intend to return, but deserta begins her 

 flight with a series of short zig-zags in the form of a half circle 



*Ants, Bees, and Wasps, p. 95. 



