164 SUPPLEMENT TO 



Eemembering tliis, it is interesting to note how 

 differently tlie tiger-beetle [Cicendela) behaves when 

 hunting the powerful harvesting ants and when 

 preying upon the weak little Formica {Tapinomd) 

 erratica ; for, while it seizes the latter without taking 

 any precautions, it is evidently more than half afraid 

 of the former. 



I have seen this beetle lying in wait near a train 

 Q>i strudor or barhara ants, watching until some indi- 

 vidual separated a little from the main body, when it 

 would rush forward and make a snap at it, retiring 

 again as quickly as it came. If the tiger-beetle fails 

 to seize its prey exactly behind the head it will let it 

 go again, and two or three ants are often thus cruelly 

 mutilated before a single one is carried off. 



No doubt the beetle has learned that if once this 

 ant clasps its mandibles upon either antennse or legs, 

 nothing, not even death itself, will make it release 

 its hold. It therefore tries to pin the ant in such a 

 way that it cannot use its formidable jaws. Perhaps 

 the habit of forming long compact trains may have 

 been acquired by the ants partly with a view to 

 guarding against attacks of this kind. 



The colonies of the little F. erratica, on the other 

 hand, apparently have to trust to their habit of 

 working under the covered ways which they con- 

 struct, as well as to their activity and great numbers 

 for their preservation. 



I had thought that the very powerful, and, to me, 

 disagreeable, odour of these little ants might have 

 rendered them distasteful to the tiger -beetle, but this 

 is evidently not the case, 



I have said above that, as far as our present know- 



