The brown recluse spider typically has a well-formed, darkly pigmented violin shape on its anterior.
Recluse spiders prefer to squeeze themselves in tight spaces and are found more commonly on rough surfaces such as paper, wood, and cardboard rather than smooth surfaces such as ceramic and metal.
In nature, they are found under rocks, particularly in dry areas and under the loose bark of dead trees. Of medical concern is that they seek refuge inside shoes, under clothes left on the floor, in gardening clothes or gloves left in the garage.
Recluse spiders produce 30 to 80 eggs per sac, which is about average for an actively hunting spider. Populations in homes can reach hundreds or thousands.