Slugs are not insects but are mullosks. They resemble snails in that they are legless, flattened soft-bodied creatures with few features other than a pair of antennae or feelers. Unlike snails, they lack shells. Young slugs may be small (1/2 inch long or less) and dull white. Older slugs are generally brown, gray or black. Some have darker spots. The largest species may be up to 7 inches long. Small slugs may simply rasp away the leaf surface. Larger slugs may eat small holes in leaves or eat large areas of leaves, especially along the margins. Silvery slime trails may be found, but the slugs usually hide beneath soil or debris during the day.