What Is This Black Footed Yellow Sac Spider?

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What is this black footed yellow sac spider? This black footed yellow sac spider is a creature that you may occasionally come across. The black-footed yellow sac spider is aptly named for its coloring and the fact that it often lives in sacs spun from silk.

While their bite may not always be deadly, it can still be painful. Additionally, these spiders leave behind silk as a form of protection. 

Continue reading to find out about the black footed yellow sac spider

What is this black footed yellow sac spider?

Agrarian Sac Spider of the species Cheiracanthium inclusum

The black-footed yellow sac spider is a spider found in the Americas. It is a member of the Eutichuridae family of spiders, including the brown recluse spider. The yellow sac spider is considered medically significant because its bite can cause necrosis (tissue death).

The black-footed yellow sac spider is a pale beige to yellow color with a tinge of green. They have dark brown chelicerae (fangs). 

Adult males and females are both 1/4 inch in body length. They are spotted more easily because of their black feet, typically found high up on the walls or ceilings. 

The black footed yellow sac spider is a member of the sac spider family. These spiders get their name from the characteristic yellow sac they carry around. The sac is used to store eggs. 

The sac’s color slightly reflects the color of the insect most recently consumed. It gives these spiders an advantage when hunting as they can better blend in with their surroundings. 

Additionally, there are variations in hue seen within different species of black footed yellow sac spiders. One of the most easily identifiable features is the dark, lance-shaped mark on their abdomen.

Information on Yellow Sac Spider – Appearance, Webs, and Eggs

Information on Yellow Sac Spider - Appearance, Webs, and Eggs

The size of males and females

This black footed yellow sac spider is a small, spindly spider that ranges from 15 to 0.31 inches. The length of the female is typically 0.20 to 0.35 inches. They can be identified by their black feet and markings on their abdomen.


What is this black footed yellow sac spider?

This spider is pale yellow-beige with black-tipped jaws and palps. It also has brown or black markings on its body and an orange-brown stripe running through its abdomen.


The black-footed yellow sac spider is a small, round-shaped spider that produces about two egg sacs each. Each egg sac contains 30 to 50 eggs, and the female stays with the eggs to protect them from predators.

The eggs are white and covered in silk. They are deposited at the bottom of leaves or other foliage and left to hatch on their own.


Spiderlings are the offspring of a spider. They hatch from a sac in the spring and stay with their mother for about 17 days. After 17 days, they will molt for the first time and become independent. The mother spider stays with her spiderlings until they complete their first molt.

The Webs

The yellow sac spider builds a sac or silken tube in protected places. Such as under leaves or at the ceiling and wall meeting point. They do not make webs but instead build a sac or silken tube to live in.

Where do yellow sac spiders live?

Adult Male Longlegged Sac Spider of the Genus Cheiracanthium

The yellow sac spider is a spider that is indigenous to the Americas and West Indies. There is also a European counterpart, called the Cheiracanthium punctorium.

This spider has traveled worldwide in search of warmth, including Africa and Réunion. They have been known to enter people’s homes or other structures during winter to escape the cold.

Where is the yellow sac spider home nest?

Where is the yellow sac spider home nest?

Sac spiders are found in many different habitats, both indoors and outdoors. They live in houses, barns, sheds, and other buildings.

The most common site for the sac is within a leaf, under landscape timbers, logs, or at the junction of wall and ceiling. Yellow Sac Spiders are often found crawling upon walls or other vertical surfaces.

Are yellow sac spiders poisonous?

Are yellow sac spiders poisonous?

The Yellow Sac Spider is not poisonous and usually only bites humans if they feel threatened. Their bites are painful and cause swelling, nausea, and other symptoms.

What do yellow sac spiders eat?

What do yellow sac spiders eat?

Yellow sac spiders are generalist predators that eat various insects, including cockroaches. If resources are limited, they will also eat their egg sacs.

Do yellow sac spiders bite?

Do yellow sac spiders bite?

The yellow sac spider is a small, yellow spider often found in the United States. It is important to be aware of these spiders as they are known to bite people. The bite from a yellow sac spider can be dangerous. It can cause symptoms about 2-8 hours after the bite.

The bite starts by resembling a mosquito sting. Then it develops into a large surface lesion (up to 10 centimeters).

Symptoms of a yellow sac spider bite

Symptoms of a yellow sac spider bite

If a spider bites you, it is essential to catch the spider and identify it. It will help you determine if the bite is dangerous and requires medical attention.

Spider bites can be dangerous if not caught in time, so it is important to seek medical help as soon as possible. The symptoms mostly include rashes, fever, nausea, and pain. 

What does a yellow sac spider bite look like?

A yellow sac spider bite is not deadly, but it can be painful. If bitten, the person may feel a burning sensation that lasts for about 90 minutes. In some rare cases, the person may feel nauseated after being bitten. 

How to get rid of yellow sac spiders in the home naturally?

The yellow sac spider is an outdoor spider found indoors around the foundation of a building or in secluded, dark areas. 

If you see these spiders around your home, there are a few things that you can do to get rid of them naturally: 

Use Different Types of Insecticides

One is to apply insecticide treatments specifically for spiders. 

Glue Traps

You can also put down glue traps to monitor activity and see if more spiders need to be removed. 


Ensure that the lights are turned off at night.

Use Technologies like searching devices to Prey on Spiders

Numerous devices help you locate spiders. You can use it for locating and eliminating them. To kill them, you can use different chemicals like borax or DE.

How to control inclusum spiders or yellow egg sac spiders?

The black-footed yellow sac spider is considered a nuisance pest and can be difficult to control. Do the following few things to help control black-footed yellow sac spiders on your property:


Reduce clutter on the exterior and interior of your property.

Seal cracks and holes

You can repair torn window screens and seal cracks and holes in your home’s exterior. Seal any gaps and cracks along the foundation of your home.


Consider using a pesticide if populations continue to grow.

Windows Repair

You can also install window screens with tight mesh and door sweeps on exterior doors.


Remove moisture sources in your home.

Trim Foliage

Keep foliage trimmed back and away from homes.


Yellow sac spiders are small arachnids that typically measure between ¼ and ⅜ of an inch in length. They have pale beige or yellow bodies, often tinted green, and the fangs and the tips of their legs are dark brown. These spiders can be found throughout North America.

In conclusion, yellow sac spiders are a type of spider that use their tubes as a safe place. They are active predators that don’t use webs for hunting. Instead, they spin silken tubes in debris, curled leaves, and other small spaces.

About the author

A biotechnologist by profession and a passionate pest researcher. I have been one of those people who used to run away from cockroaches and rats due to their pesky features, but then we all get that turn in life when we have to face something.