Yellow Sac Spider

Among the most common spiders found in the home, the Yellow Sac Spider is most evident in the sac it spins to rest in throughout the day, coming out at night to hunt. The sacs are found on the back of furniture, along baseboards and in corners where the wall meets the ceiling. Outdoors, you will find the sacs within rolled up leaves, under stones and behind the bark of trees.

Yellow Sac spiders are about 1/4 of an inch long and are a pale yellowish-green. They generally eat small insects and other spiders, searching for trapped potential food sources at night. They mate only once, and females typically produce two sets of eggs, the first two weeks after mating. They hatch quickly, and the female stays with the young about two weeks. The second set of eggs is produced two weeks after the young disperse.

Because of its proximity to people, this spider accounts for more human bites than any other spider in the U.S. Such a bite is rare, however, and generally causes no ill effects. The venom from a Yellow Sac Spider usually causes a small red welt and a pustule at the bite site.

Perimeter spray is helpful to control the population of these spiders. You can reduce numbers by removing the sacs when they are discovered in and around your home.