The black widow's appearance depends on gender. The legs of the female look like they are stretching outwards from the body. Her body is black, except for a red hourglass marking on the underside of the spherical abdomen. Coloration of the marking can be yellow, and instead of an hourglass, a black widow might display two spots of color.
The male black widow is smaller than the female, and he is not as darkly colored. A stripe down the back of the male is red or light brown. Streaks of color, either white or yellow, go out from this stripe.
When threatened, the female black widow might bite. This is not the case with the male black widow.
The brown recluse spider's body is golden brown or tan. Its head has a darker marking shaped like a violin. The legs look like they are stretching away from its body. The spider has six eyes, one on either side of a pair that faces front. The size of the brown recluse, including its legs, ranges from the width of a quarter to the width of a half-dollar. The fangs of the brown recluse are small. Like the black widow, it bites people only when threatened.
The black widow prefers dry, sheltered places. In the United States, this spider is more common in the Southeast. In a home setting, they usually reside in places such as attics, basements, closets, sheds, garages, woodpiles and crawlspaces as well as outhouses.
The brown recluse prefers the same kind of undisturbed places that the black widow does. In the United States, this spider is most common in the Southeast and the Midwest.
Black widows make tangled webs that capture prey. They eat such things as centipedes, small reptiles, other spiders and small mammals. These spiders hang upside down in tangled webs that have no regular shape.
Although brown recluse spiders do spin webs, they tend to use them as a "retreat." The male brown recluse is a hunting spider: It tracks down prey instead of using its web to capture it. The female uses its web to ambush prey. Brown recluses hunt at night, and they eat such things as crickets and flies. Brown recluses also scavenge, eating things that are already dead.
Most black widow bites do not kill people. Instead, the black widow's bite makes them very sick for two to five days. When a black widow bites, the person feels a sharp prick, as with a pin.
As with the female black widow's bite, the brown recluse's bite does not often kill, instead making people very sick. Unlike the black widow's bite, a person who is bitten by a brown recluse will not feel it at first. A dangerous infection can develop around the bite. Because the brown recluse has small fangs, it cannot bite through clothes.