Silverfish are wingless insects 1/2 inch long when fully grown. The Silverfish is covered with silvery scales. The female lays groups of less than 60 eggs at once, deposited in small crevices. The eggs are oval-shaped, whitish, about 0.8 millimeters (0.031 in) long, and take between two weeks and two months to hatch. Silverfish usually lay fewer than 100 eggs in their lifetime. When the nymphs hatch, they are whitish in color, and look like smaller adults. As they molt, young silverfish develop a greyish appearance and a metallic shine, eventually becoming adults after three months to three years.