The Wonderful Ways of Insects and Spiders 



materials, as a protective covering for their caterpillar-like bodies. 

 Those that use sticks are said to construct "log cabins." More 

 commonly they use sand or bits of vegetable matter which adhere 

 to their bodies with silk produced by certain glands. 



THE CADDIS FLY -NATURE'S MASTER BUILDER 



In the larval stage this small mothlike insect, living at the bottom of a pond or 

 stream, builds a case about itself from bits of plants or pebbles. (Both types are 

 pictured underwater.) The cases, held together with gluelike silk provided by the 

 creature's secretions, are remarkable for their skillful construction. 



Still another interesting product of some caddis worms is a 

 silken net. The insect anchors this so that the cup-shaped interior 

 faces upstream. Thus the net serves both as protection against the 

 current and as a food trap for the caddis worm that fashioned it. 



The caddis fly emerges from its pupal form in a manner differ- 

 ent from that of most water insects. The usual way is for them 

 to leave the water before they attain adult form; but the caddis 

 fly emerges at the bottom of the stream and swims to the surface. 



