Brown Recluse Spider
Size: About the size of a U.S. quarter (poker chip)
Color: Tan to dark brown, abdomen and legs are uniformly colored with no stripes, bands, or mottling. The legs are long and thin and lack conspicuous spines.
Features: Dark violin-shaped mark on back, with the neck of the violin pointing toward the rear (abdomen) of the spider. This feature is consistent in adult brown recluses, but can be hard to see and is less obvious in younger spiders. Also, brown recluses only have six eyes: most Kentucky spiders have eight.
Notes: Bites are very serious and require immediate medical attention, but brown recluses are timid and unlikely to bite unless handled. These spiders are more common in Western KY, less common in Central and Southeastern KY. They tend to occur in hidden locations indoors and outdoors: piles of cardboard or paper, stacks of cut wood, and wall-voids of buildings.
Read more at: https://entomology.ca.uky.edu/ef631