The redback is a webbing spider as opposed to a crawling or hunting spider. The female is the largest at 12-15mm while the male is much smaller at 3-4mm and is rarely seen. The redback has a large bulbous abdomen with the famous red or orange stripe appearing on the top. The legs are long and thin, tapering at the ends. The male is a different colour to the female, usually with a white abdomen with 4 black bars on each side.