134 ANIMAL STUDIES 



this group of insects. These extend all over the world, 

 being particularly abundant in the warmer countries, and 

 their strong biting mouth-parts and voracious appetites 

 render many of them dreaded pests to the farmer. The 

 cockroaches are nocturnal in their habits, racing about at 

 night, devouring victuals in the pantry and gnawing the 

 bindings of books. During the day their flat bodies enable 

 them to secrete themselves in crevices wherever there is 

 sufficient moisture. 



In the grasshoppers, locusts, katydids, and crickets the 

 body is more cylindrical, and the hind pair of legs are often 

 greatly lengthened for leaping. The crickets and katydids 



are nocturnal, the former re- 

 maining by day in burrows 

 which they construct in the 

 earth, the latter resting qui- 

 etly in the trees. At night 



FIG. 76. The Rocky Mountain locust. 



After RILEY, from The insect World. they least upon vegetable 



matter principally, though 



some species are known to prey on small animals. Those 

 insects we usually term grasshoppers (properly called lo- 

 custs) are specially destructive to vegetation. Some spe- 

 cies are strong fliers, and this, connected with their abil- 

 ity to multiply rapidly, renders them greatly dreaded pests. 

 They have been described as flying in great swarms, form- 

 ing black clouds, even hiding the sun as far as the eye 

 could reach. The noise made by their wings resembled 

 the roar of a torrent, and when they settled upon the earth 

 every vestige of leaf and delicate twig soon disappeared. 



The eggs of the majority of Orthoptera are laid in the 

 ground, where they frequently remain through the winter. 

 When hatched the young quite closely resemble the parents, 

 and, after a relatively slight metamorphosis, assume the 

 adult form. 



127. Dragon-flies, may-flies, white ants, etc. The dragon-, 

 caddis-, may-flies, ant lions, and the white ants possess four 



