William Hamilton Maxwell,The Field Book or Sports and pastimes of the United Kingdom , Londres, Bradbury & Evans, 1833, p. 87.

Caddis or Cad-bait,  A kind of worm or grub.

The several kinds of cadews in their nymphs, or maggot state, thus house themselve ; one sort in in straw , called from thence straw-worms ; others in two or more parallel sticks, creeping at the bottom of brooks; a third, in a small bundle of pieces of rushes, duckweed, etc., glued together, therewith they  float on the surface, and can row themselves  about the water with the help of their foot ; both these are called cad-bait. It is a curious faculty that these creatures possess, of gathering such bodies as are fittest for their purpose, and then so glueing them together, some to be heavier than water, that the animal may remain at bottom where its food is, and others to be so buoyant as to float, and there collect its sustenance ; these houses are coarse, and show no outward an, but arc within well tunnelled, and have a tough hard paste, into which the hinder part of the maggot is so fixed, that its cell can be drawn after it without danger of leaving it behind, and it can also thrust out its body to reach the needful supplies, or withdraw into its covering for protecting and safety.

William Hamilton Maxwell,The Field Book or Sports and pastimes of the United Kingdom , Londres, Bradbury & Evans, 1833, p. 87.