Yellow Sac Spiders
Active Seasons




Appearance and Size Facts
- Yellowish in color, with dark markings on the mandibular palps, chelicerae (jaws), and tarsi (feet)
- It is one of a only a few spiders in North America considered to be medically significant
- Size: Relatively small, approximately 1/4 inch
- Derive their name from the sac of silk they produce daily for resting
- Very active, nocturnal "hunt and seek" spiders
Behavior and Habitat of Yellow Sac Spiders
Yellow Sac spiders derive their name from the sac of silk they produce daily for resting. Indoors, these small, white, paper-like sacs are often found along ceilings and corners, or behind pictures and shelves. After mating, females lay 30-48 eggs, cover them in a thin, white silken sac and guard them. The egg sacs may be found in protected areas, or even wrapped in a folded leaf. All stages of sac spiders make a silken cell (the ""sac""), in which they rest when not active. Indoor populations of C. inclusum are non-seasonal and can be adults at any time. Usually found in foliage, but some species are found inside houses and around other human developments. The American Yellow Sac spider builds a sac-like silken tube in foliage or under bark or stones for a daily resting place.

Signs of Infestation of Yellow Sac Spiders
Bites by American Yellow Sac spiders generally produce instant, intense stinging pain, not unlike that of the sting of a wasp or hornet. This may be followed by localized redness, swelling and itching. These manifestations may or may not evolve into a necrotic lesion, but when that occurs, healing is usually complete within eight weeks. They are very prone to bite defensively (more so than any other significantly venomous U.S. spider), and some bites in humans have occurred in unusual places, such as in automobiles and swimming pools.

Tips for Prevention of Yellow Sac Spiders
Web removal with broom or vacuum.

Yellow Sac Spider Gallery


Latest Pest & Termite Control News

New Year Pest Control Resolutions for Your South Florida Home
Dec 19, 2022—Rodents, Pest Control, Rodents
A new year means new pests are trying to call your South Florida house their home. This year, along with new year’s resolutions to improve your health, finances, attitude, and whatever other things you want to change in your life, make this year the year you keep your South Florida home...
Read More ›
Expert Advice on Protecting Your Home and Lawn from Pests this Winter
Dec 08, 2022—Florida Lawn Care
Living in South Florida means rodents, ants, and other pests don't take the winters off! Meanwhile, your lawn needs less watering and mowing during the winter months and is susceptible to various diseases such as brown patch fungus. Your lawn in winter While we’re outdoors, let’s talk...
Read More ›
Be Thankful for a Pest-Free Home This Holiday Season
Nov 15, 2022—Pest Control, Tips & Control Advice
Thanksgiving starts off the holiday season in grand style with a sumptuous feast surrounded by family and friends. If you’re hosting one of these Thanksgiving gatherings, you‘ve probably got a lot on your to-do list getting ready for the big day. Pests, such as roaches, ants, and...
Read More ›