The United States has several species of tarantula which are brown in coloration. Most are found in the Southwest desert.
Tarantulas are among the largest spiders, with some U.S. species reaching a leg span of almost 13 cm. Their size can be intimidating and frightening to people. While large and scary-looking, U.S. tarantulas do not possess venom deemed to be medical concerning. Bites are possible if a tarantula is provoked, but they prefer to run or use itchy hairs they fling. Females can live upwards of 30 years and are not likely seen since they prefer to stay in their burrows. Males, however, are most likely encountered when they roam in search of females with which to mate. As they roam the males can wander indoors or onto roads where they often are run over by vehicles.