The sand collar of northern moon snail, Euspira heros, off the coast of New Jersey, USA. The sand collar is a mixture of sand, mucous, and eggs. Moon snails have huge appetites and eat several times a day, they mainly eating other mollusks. Moon snails drill holes into bivalves by rasping with their file-like radular tongue. The moon snail has a special egg case called a collar. The collar is so delicate that you could crush it in your hand. Some live moon snails have strong intense color.