Because they have a very short focal length, wolf spider eyes don't change focus, therefore they enjoy excellent depth perception for objects at close range. A front view of a typical wolf spider, showing the arrangement of the eight eyes and impressive fangs. Wolf spiders are included in a larger group of similar creatures collectively called hunting spiders. Lycosids, a more scientific name for wolf spiders, are some of the swiftest of all, running almost two feet a second, but at this speed after a few seconds they are thoroughly exhausted. Like any good sprinter who values his track shoes, wolf spiders gain traction with adhesive hairs on the soles of their feet.
Sprints are necessary mostly to escape danger or to pursue prey.
Once a victim is spotted, the chase is soon over and the hapless locust or beetle is quickly grabbed, injected with paralyzing venom, and its now-dissolved tissues sucked out. Like other spiders, lycosids extend their legs hydraulically by an increase in blood pressure, but contract them with muscles. If a wolf spider is injured enough to lose blood, it will run a short distance, then stop and be unable to move again. Lycosids range widely throughout all kinds of habitats. I've watched one species construct silk-lined burrows in southern sand dunes, and there they spend the hot day, emerging at dusk to hunt for food through the night.