Order: Araneae

Family: Theridiidae

This spider gets its common name because it is the most common spider encountered indoors. It is considered a nuisance pest and is found throughout the United States.

Description: The adult female ranges in size from 3/16" to 5/16" long. Males are slightly smaller. Adults vary in color from yellowish brown with a dirty white abdomen and dark markings to almost black with dark stripes. Females have yellow legs, while the male's legs are orange. Both sexes have dark rings around the legs.

Biology: Adult females lay about 250 eggs in a brown silky sac. This sac is affixed to the web, but will be moved if temperature or disturbance conditions prevail. A female can produce as many as 4000 eggs in her lifetime. Adult house spiders can live approximately one year.

Habits: House spiders randomly build webs until a good site is located to catch prey. They prefer places with higher humidity. This can result in excessive webs in a short period of time. Inside structures, house spiders are likely to be found around window frames, in closets or up high in corners of rooms.