Slugs and woodlice are the worst enemies of mushroom crops.
In external form Trilobites are not unlike Isopod Crustaceans, especially the terrestrial species commonly called "woodlice"; and until the nature of their appendages was known, it was thought by some authorities that the two groups might be related.
Like the woodlice they were capable of rolling themselves up into a ball, many specimens having been found fossilized in this state, with the pygidium pressed tightly against the head-shield.
Wingless females of many tropical species present a close superficial resemblance to woodlice; and one interesting apterous form known as Pseudoglomeris, from the East Indies, is able to roll up like a millipede.
CRUSTACEA, a very large division of the animal kingdom, comprising the familiar crabs, lobsters, crayfish, shrimps and prawns, the sandhoppers and woodlice, the strangely modified barnacles and the minute water-fleas.