162 FABRE'S BOOK OF INSECTS 



and so are other female Locusts in varying degrees with four 

 short tools, arranged in pairs and shaped like a hooked finger- 

 nail. On the upper pair, which are larger than the others, 

 these hooks are turned upwards ; on the lower and smaller 

 pair they are turned downwards. They form a sort of claw, and 

 are scooped out slightly, like a spoon. These are the pick- 

 axes, the boring-tools with which the Grey Locust works. 

 With these she bites into the soil, lifting the dry earth a little, 

 as quietly as if she were digging in soft mould. She might be 

 working in butter ; and yet what the bore digs into is hard, 

 unyielding earth. 



The best site for laying the eggs is not always found at the 

 first attempt. I have seen the mother make five wells one 

 after the other before finding a suitable place. When at last 

 the business is over, and the insect begins to rise from the hole 

 in which she is partly buried, one can see that she is covering 

 her eggs with milk-white foam, similar to that of the Mantis. 



This foamy matter often forms a button at the entrance 

 to the well, a knot which stands up and attracts the eye by 

 its whiteness against the grey background of the soil. It is 

 soft and sticky, but hardens pretty soon. When this closing 

 button is finished the mother moves away and troubles no 

 more about her eggs, of which she lays a fresh batch elsewhere 

 after a few days. 



Sometimes the foamy paste does not reach the surface ; 

 it stops some way down, and before long is covered with the 

 sand that slips from the edge. But in the case of my Locusts 

 in captivity I always know, even when it is concealed, exactly 

 where the barrel of eggs lies. Its structure is always the same, 

 though there are variations in detail. It is always a sheath 

 of solidified foam. Inside, there is nothing but foam and eggs. 

 The eggs all lie in the lower portion, packed one on top of 

 another ; and the upper part consists only of soft, yielding 

 foam. This portion plays an important part when the young 

 larvae are hatched. I will call it the ascending-shaft. 



The wonderful egg-casket of the Mantis is not the result of 



