THE ANT-LION. 183 



tion 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 swiftness of 

 foot would otherwise render it imj)ossiLle 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 con- 

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



A " 



« 



f 



Grub of the Ant-Liuii, masuiaed, with ouc perfect Trap, and aiiuther begun. 



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

 to stumble over the margin, and cannot, from the loose- 

 ness 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 

 of various dimensions, from one to nearl}^ three inches in 

 diameter, according to circumstances. 



