DESCRIPTION: L= 0.75" (19mm).  All brown with difficult-to-see, violen-shaped marking right behind eyes. Brown Spiders have only 6 eyes (unlike most spiders which have 8), and the eyes are arranged in three pairs (see Vetter 1999 for more information).
NATURAL HISTORY: Dangerously Venomous (potentially fatal -- when stung, call the Arizona Poison and Drug Information Center at 626-6016 in Tucson and 1-800-362-0101 elsewhere in Arizona.). The venom generally causes a sore that enlarges over time (see picture to right) and may cause permanent tissue damage (and possible death) if not treated by a physician (see Vetter and Visscher 1998 for more information). Brown spiders use irregular webs built underneath rocks and debris to catch their arthropod and other invertebrate prey.
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