Stuard Ward Frost, Ancient artizans, the Wonders of the Insect World, Boston, The Van Press, 1936.
The workers of stone are perhaps the most interesting of all the masons, The writer refers especially to the larvae of the caddice flies, that live in the waters of streams and pools. Not all of these are stone workers for some build cases of moss, grass, sticks, shells and in fact a great variety of materials. Some live in stagnant water while others inhabit fresh running water. Those building stone houses live in swiftly flowing water and no doubt learned at an early date that stones were more suitable for they need sinkers to hold them down. These cases serve as shelters in which the soft tender caddice worm hides protruding only the head and fore end of the body. It feeds upon small organism and breathes the air incorporated in the water. It can move about carrying its case or home wherever it goes. When ready to change to a full-grown insect it crawls within the case, procures a stone to partly close the opening and then rests as a pupa for several days. Finally a four winged, hairy moth-like insect emerges with long antennae which are characteristic of this insect.
Caddice worms, especially those that live in stagnant water, make great pets for an aquarium. Their peculiar manner of carrying their homes or cases about with them as they go is a never ending source of amusement. When at rest the insect is completely concealed by its case and it resembles a sheap of sticks or stones. If one of the experimental disposition he can remove the case and substitute bits of micca or colored glass and in time the caddice worm will build itself a transparent case through which all the activities of this elusive creature can be studied.
One frequently finds in stagnant or brackish water little bunches of sticks that move about the bottom of the pond. These are the cases of caddice worms. Some species apply the sticks lengthwise while others arrange them crosswise. The fragments are held together by means of silk spun by the worm. The completed structure serves as a hiding place from which the worm protrudes its head and fore end of the body including the legs. It is then able to walk about and carry its home wherever it goes. As it grows it increases the size of its case by adding to the larger end. Both ends of the case are open and it breathes by removing air from the water as it passes through the case. It feeds upon the micro-organisms that are always very abundant in stagnant water. In speaking of the massons we described the caddices worms that constructed stone houses. Still other species build houses of shells, moss, sand and a greayt many other materials.