Insects on the Farm 157 



unlike the mature butterfly stage. Again, only the closest 

 watching of the life history of the " wiggle-tail" convinces 

 us that it is a mosquito in another form. The little 

 "worm" (larva), found in the plum, is quite different 

 from the shy curculio beetle that laid the egg. (Fig. 95.) 

 Grasshoppers, squash bugs and crickets are examples of 

 insects which attain maturity by gradual growth with- 

 out distinct stages. (See Fig. 99.) 



227. How Insects Differ from Other Animals. Insects, 

 like the frogs and snakes, are cold-blooded animals. 

 The temperature of their bodies changes with that of 

 the air or water, in whichever they happen to be. When 

 cold weather comes, many kinds find shelter under fallen 

 leaves, sticks, or may burrow into the ground and there 

 remain quiet until warm weather returns. This way of 

 passing the winter is called hibernation. While hibernat- 

 ing, they may be frozen stiff, or the eggs and larvae may 

 be frozen; but when the weather becomes favorable, 

 many kinds will move about just as lively as ever. 

 Severe freezing may kill some, but many will survive. 

 The propagation of some sorts is dependent on the 

 ability of the eggs to withstand the winter. Higher 

 animals have the bony skeleton inside of the body, but 

 insects have the hard bony part on the outside. The 

 muscles of insects are attached to the outer body wall and 

 not to internal bones, as in other animals. Insects do 

 not breathe through a mouth, but have little breathing 

 pores along the sides of the body. The nerves of the 

 insect that detect odors and guide it to its kind and food 

 are usually in the little "feelers," or antenna, or sometimes 

 in the segments of the legs. 



Some species of insects die soon after laying eggs, 

 often before the eggs hatch, as the tent caterpillar; others 



