John T. Coleman, History of the early settlement of Bowmanville and vicinity, Bowmanville (Ont.) West Durham Steam Print & Pub. House, 1875. p. 29.

The idea, no doubt, originated front the habit of some of the Caddice Worms, which live inside of tubes constructed by themselves, of different materials, such as grains of sand, leaves, bits of wood, straws, and hairs. These worms are common to fresh water streams and ponds ; several of them can be seen together in a still, deep part of our creeks, or springs, with their heads protruding from their portable dwellings, and when disturbed, withdrawing entirely within their tubes.