Many people are familiar with the secretive and dangerous brown recluse spider, particularly its unique fiddle- or violin-shaped marking that appears on the top, or dorsal side, of the spider. In fact, the brown recluse is sometimes called the “fiddle-back spider.” The spider is typically tan, brown, or yellowish in color, and the unique fiddle shape tends to be darker than the spider's body. The neck of the fiddle points downward toward the spider's abdomen.
Like all spiders, the brown recluse has eight legs and no antennae or wings. Their bodies consist of two sections-the cephalothorax, which is the head and thorax combined, and the abdomen. Brown recluse spiders have six eyes-three pairs situated in a semi-circle pattern. The brown recluse is not the only spider whose eyes are arranged in this way. However, this arrangement combined with the fiddle-shaped marking help distinguish the brown recluse from other species.
An adult brown recluse spider is about ¼” to half an inch in length. Including its legs, the spider measures about one inch in diameter. The male spiders are a bit smaller than the females, though their legs tend to be longer. The brown recluse's legs are thin and long, while the abdomen is bulbous and covered with fine hairs, giving it a velvety appearance. The legs and abdomens of the brown recluse are uniform in color, so a spider that has more than one color on its legs or abdomen is not a brown recluse.
Young spiders look a great deal like the adults except that they are lighter in color and smaller.
Brown recluse spiders get their name for obvious reasons: first, because of their color and second, because of the fact that they prefer to be reclusive, which means they are secretive and prefer to stay hidden from view.