Fig. 190.—Hills of the white ant.
The cunning and intelligence of white ants are well displayed in their attacks upon houses. Having decided to enter a house, they begin to tunnel some distance away, and finally reach the corner post or some timber that enters the ground. With remarkable speed the workers enter this, hollowing it out, until it is nothing but a shell. They eat to the very surface, leaving only a faint ghost of a partition, and what appears to be a solid block is really so thin that a finger can be thrust through it. So clever are these little ant miners that they have been known to come up through the floor directly beneath the leg of a chair, and burrow and eat up through it, so completely devastating it that when the owner moved it the small hole in the floor appeared and the chair fell in pieces.
In the Isle of France a new building was ruined by these insects in a few months; and at Colombo a large house suddenly fell in over the heads of the occupants, the beams being crushed like egg shells. The work they accomplished in this way would hardly be credited were it not for the substantiated statements collected by the authorities in the countries where they are mostly found.
The so-called caddis worms (Fig. 191) are merely the larvæ of the caddis fly which incloses itself in a case that is often decorated in a singular way. The cases of a number of the worms placed together display a striking variety of designs. Some roll up leaves; others spin a silken thread from the mouth and bind pieces of leaves together, attaching other pieces to it.
Fig. 191.—Caddis worm and case.