118 ANIMAL FORMS 
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- 
So etly in the trees. At night 
Fig. 70.—The Rocky Mountain locust.— 
After Rizr, from The Insect World. they feast 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. 
117. Dragon-flies, may-flies, white ants, etc. (Neuroptera).— 
The dragon-, caddis-, may-flies, ant lions, and the white ants 
