Slugs are mollusks, related to oysters and clams. Slugs are referred to a "naked snails," as they possess no shell. Slugs lay clusters of translucent, pearly-shaped eggs under debris or buried beneath the soil surface. They can lay between 20 to 100 eggs several times per year, taking approximately two years for slugs to reach maturity. The gray garden slug, Peroceras reticulatum, is the slug generally encountered in Illinois. It is approximately 3/4 to 1-1/2 inches long, ranging in color from pale yellow, lavender, to purple. In addition, they are covered with black or brown spots and mottling. Less commonly encountered is the great gray garden slug, Limax maximus.