212 INSECT ARCHITECTURE. 



operation — the one, namely, which is nearest the 

 centre of the circle. Were it to employ the others 

 in digging away the sand, it would encroach upon the 

 regularity of its plan. Working with great industry 

 and adroitness in the manner we have just described, 

 it quickly makes the round of its circle, and as it 

 works backwards it soon arrives at the point where 

 it had commenced. Instead, however, of proceed- 

 ing from this point in the same direction as before, 

 it wheels about and works a round in the contrary 

 direction, and in this way it avoids throwing all the 

 fatigue of the labour on one leg, alternating them 

 every round of the circle. 



Ant-Lion's Pitfalls, in an cxperimenting-boi. 



Were there nothing to scoop out but sand or loose 

 earth, the little engineer would have only to repeat 

 the operations we have described, till it had completed 

 the whole. But it frequently happens in the course 

 of its labours, sometimes even when they are near a 

 close, that it will meet with a stone of some size which 

 would, if suffered to remain, injure materially the 

 perfection of its trap. But such obstacles as this do 

 not prevent the insect from proceeding ; on the con- 

 trary, it redoubles its assiduity to remove the obstruc- 

 tion, as M. Bonnet repeatedly witnessed. If the 

 stone be small, it can manage to jerk it out in the 

 same manner as the sand ; but when it is two or 



