Answer: caddisfly

AnswerCrossword Clue
CADDISFLYInsect
caddisflyA small, mothlike insect with an aquatic larva that typically builds a protective, portable case of sticks, stones, and other particles. Some kinds have been traditionally used as bait by fishermen
caddisflyany small mothlike insect of the order Trichoptera that lives near, and lays its eggs in, water