228 



Insect Architecture. 



supposed that he had discovered its mouth. Its habits re- 

 quire that it should walk backwards, and this is the only 

 species of locomotion which it can perform. Even this sort 

 of motion it executes very slowly ; and were it not for the 

 ingenuity of its stratagems, it would fare but sparingly, 

 since its chief food consists of ants, whose activity and swift- 

 ness of foot would otherwise render it impossible for it to 

 make a single capture. Nature, however, in this, as in 

 nearly every other case, has given a compensating power to 

 the individual animal, to balance its privations. The ant- 

 lion is ,slow, but it is extremely sagacious ; it cannot follow 

 its prey, but it can entrap it. 



The snare which the grub of the ant-lion employs consists 

 of a funnel-shaped excavation formed in loose sand, at the 



Grub of the Ant-Lion, magnified, witlh me perfect Trap, and another begun. 



bottom of which it lies in wait for the ants that chance to 

 stumble over the margin, and cannot, from the looseness of 

 the walls, gain a sufficient footing to effect their escape. 



By shutting up one of these grubs in a box with loose 

 sand, it has been repeatedly observed constructing its trap 



