Category: Spiders

Yellow Sac Spider



Size Length: 1/2"
Width: 1/8"

Color Brown



Yellow Sac Spiders are relatively small (10 mm body length), and are yellowish in color; they are difficult to distinguish from one another.


Some yellow sac spiders are attracted to the smell of hydrogen oxide in gasoline. An unusual double pipe configuration in the Mazda6 led to a recall of around 65,000 Mazda6 vehicles in the U.S, Canada, Mexico and Puerto Rico from the 2009-10 model years after it was found that yellow sac spiders were building nests in the fuel line of the vehicles.


In the autumn the food is disappearing so the yellow sac spider seeks indoor refuge to find food. Indoors it is often seen on walls and around different constructions. If disturbed it drops to the floor. Egg sacs are laid in corners of all sorts. The egg sacs are white and spun with silk. The female may guard her egg sac one way or the other, so be careful when removing egg sacs from around your home.

During the summer when there’s plenty of food the yellow sack spider prefers to live on trees, shrubs, and in low vegetation close to open expanses, such as fields. Occasionally it is found in cotton crops.


Bites 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. Side effects may include chills, fever, headache, dizziness, nausea, anorexia, and sometimes shock.


To protect your house from yellow sac spiders you can install tight fitting screens on windows and doors. You can also seal any crack or crevice a spider can fit into or get access to your house through. Installing yellow light on your front and back porch might also attract fewer insects, which are food for most if not all spiders.

Causes Property

Inhabit Nearby

Require a Water

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