We receive many calls from clients concerned about whether a spider is poisonous or not. Many spiders are harmless to humans and are considered beneficial because they prey on flies, crickets, ants and other insects. Humans are rarely bitten unless held or accidentally trapped.
Most spiders have fangs too small or too weak to puncture human skin.
Of the hundreds of spiders found in Tennessee, the most common poisonous species are the black widow and brown recluse. Both species have markings which can be used to distinguish them from other less threatening species. The brown recluse has a dark violin-shaped marking on the cephalothorax. Within the base of that marking are three pairs of eyes arranged in a semicircle. Black widows appear velvety and an hour glass marking on the underside of the abdomen is characteristic of this species.