- Color: either pale yellow to pale green or orange brown to red
- Size: the bodies of female sac spiders are about 3/16 to 3/8 inch long; males are smaller than the females, 1/8 to 5/16 inch long.
Sac Spider Habits:
- Sac spiders lay their eggs in a loose mass covered with a thin white silk sac.
- Eggs are often laid in indoor retreats guarded by the female; however, eggs can also be found outdoors within rolled leaves.
- Females produce several egg masses during their lifetimes.
- Sac spiders are commonly found indoors. Their numbers increase significantly in the fall when the weather turns cool and their food supply disappears.
- They enter structures through faulty screens, cracks around doors and windows, and gaps around pipes, wires, and vents in exterior walls.
- If food is available, they enter and remain in wall voids and crawlspaces.
Damage From Sac Spiders:
- Sac spiders are of medical importance because, as a group, they are responsible more than any other species for spider bites within the United States; bites often go unreported because the spider goes unseen or the bite is not felt. Most bites occur when the spider crawls into clothing and is pressed close to the skin. In most cases, the bite produces no more than localized redness, slight swelling, and a burning sensation at the site.
- Spiders in the silk retreats they build in upper corners and the joints between walls and ceilings indoors which is where they remain during the day.
- Spiders outdoors among rocks and wood piles, under decks and benches, around window and door frames, roof eaves, soffits, behind shutters, in protected areas ( e.g., barns, outbuildings, sheds, meter boxes, brick veneer, pump houses), on tall grass, weeds, and leaf litter.
How to Control and Kill Sac Spiders:
- Clutter and debris inside structures and scrap lumber, woodpiles, rocks, landscape timbers, and other protective outdoor materials should be removed.
- Both indoors and out, a vacuum cleaner with a crack and crevice attachment should be used in order to remove spiders, sacs, and egg sacs; then the bag should immediately be sealed and discarded. Special attention should be paid to upper corners where all sacs should be removed.
- Trees and bushes should be trimmed back so that they do not contact the structure, and the grass should be mowed.