Brown recluse spiders belong to a group of spiders commonly known as violin spiders or fiddle backs. This is because of a characteristic fiddle-shaped pattern they have on their head region. The spider is golden brown with the fiddle being dark brown or black. This spider is not hairy and the fiddle pattern is often shiny. They are about 1/4 to 3/4 inch long. Members of this small family are known for their poisonous venom. They have six eyes in three pairs. The cephalothorax is rather flat above and has a conspicuous, lengthwise furrow in the midline at the rear third. Each foot has two claws. Many of the wolf spiders are similar in appearance and have similar markings as the brown recluse. They are large, robust, hairy, and therefore they can be distinguished from the brown recluse.

These spiders spin small, irregular webs under bark, stones or other secluded areas. Their venom is especially poisonous to people; those bitten often become ill and find that the wound does not heal quickly. Both male and female recluse spiders, as well as their spiderlings, are capable of injecting venom which may result in serious lesion formation or systemic reactions. The severity of the bite may vary. The symptoms may vary from no harm at all to a reaction that is quite severe. Usually, the brown recluse spider bite is not felt and the pain sets in from six to eight hours later. A typical bite area may resemble a pimple, postule or blister formation within six to 12 hours later. Mild to severe pain accompanied by swelling may occur during this interval. The surrounding tissue begins to darken, is irregular in shape with sharply raised edges resulting in a sunken area which may be several centimeters in diameter. Often there is a systemic reaction within 24-36 hours characterized by restlessness, fever, chills, nausea, weakness, and joint pain. Where the bite occurs there is often tissue death and skin is sloughed off. In some severe cases, a wound may develop that lasts several months. In all cases, a physician should be notified. If at all possible, kill and take the spider to the physician for positive identification. Individual spiders can be crushed underfoot or sprayed with an aerosol spray.