A male wolf spider, with two medium eyes on the side of the head, and two large eyes above a row of small eyes.
Credit: Cathy Keifer | Shutterstock
The name “wolf spider” encompasses a large family of spiders, most of which are large, dark-colored and athletic. They belong to the genus Lycosa, which means “wolf” in ancient Greek. Unlike most spiders that catch their prey in webs, wolf spiders violently hunt it down using their strong bodies and sharp eyesight. These spiders also exhibit unique parenting habits that are of great interest to scientists.
Wolf spiders live almost everywhere in the world. They are especially common in grasslands and meadows, but also live in mountains, deserts, rainforests, and wetlands — anywhere they can find insects to eat. There are about 2,300 species of wolf spiders, and 200 that live in the United States.
Wolf spiders are usually brown, grey, black or tan, with dark body markings — most commonly stripes. Their coloring is effective camouflage, helping them catch their prey and keep safe from predators. They range from a quarter of an inch to over an inch (6.4 millimeters to 3 centimeters) long, with males typically smaller than females.
Wolf spiders’ eight eyes are arranged in three rows, with two medium-size eyes placed to the sides of the top row, two large eyes in the middle row, and four smaller eyes in the bottom row. They have excellent night vision, and primarily hunt in the dark.
Wolf spiders will bite when threatened but their venom is nominally harmful to humans. Human victims may exhibit some redness or swelling but no serious medical problems have ever been reported.
Habits and feeding
Wolf spiders are solitary creatures that roam alone in the night, stalking prey. They typically live on the ground, though some are known to climb partly up trees or dive into water to catch their prey. Some species hide in vegetation or leaf litter, while others dig tunnels or use other animals’ tunnels. Some wolf spiders hunt in a set territory and return to a specific place to feed, while others wander nomadically with no territory or home.
Wolf spiders eat mostly ground-dwelling insects and other spiders. Especially large females might eat small vertebrates. Some species chase down and grab their prey, while others wait for it to walk by and ambush it. Wolf spiders often jump on their prey, hold it between their legs and roll over on their backs, trapping their prey with their limbs before biting it.
Wolf spiders use their keen eyesight, camouflage coloring, speedy movements and high sensitivity to vibrations to be aware of and keep safe from predators. They will bite when threatened.
Wolf spiders, who use their eyes more than many other types of spiders, use visual cues in mating. The males signal their interest to females by waving their pedipalps (short limbs near their mouths) in special patterns or banging them together.
After mating, female wolf spiders lay several dozen eggs or more and wrap them in silk, creating a large egg sac about the size of a pea. The female keeps the egg sac close; if she is a nomadic species, she will carry it with her under her abdomen everywhere she goes. Tunnel dwellers leave their egg sacs in the tunnel when hunting, but bring it outside during the day because the warm sun helps the eggs develop faster. If the female is separated from the egg sac, she will search furiously for it. Mothers are known to exhibit aggressive behavior when carrying their egg sacs.
This maternal behavior doesn’t stop after the eggs hatch. After the babies are born, they crawl onto the mother’s back. She carries them there for several weeks or longer until they are large enough to venture off on their own.
Male wolf spiders typically live for one year or less, while females can live for several years.