Moon snails live on sandy substrates, at a great variety of depths depending on the species (from the intertidal zone to thousands of meters in depth). They are often seen ploughing along in the sand searching for prey feeding mostly on bivalves. They will also attack almost any other shelled mollusk they encounter in the sand including other moon snails. The moon snail envelops the prey and then bores a hole through the shell using its radula and an acid secretion. Once the shell is bored open, the proboscis is used to consume the flesh of the prey. The hole in the shell, which has a "countersunk" appearance with chamfered edges, and which varies in size according to the species, is a characteristic diagnostic sign of moon snail predation. In the breeding season, the female moon snail lays a rather stiff egg mass which includes sand and mucus. These objects wash up on sandy beaches fairly often, and are known by the common name "sand collars" because of their resemblance to an old-fashioned removable shirt collar or false-collar.