There are thousands of various spiders which may invade human dwellings, and yellow sac spider infestation appears to be one of the most widespread problems in many European and Asian…

Basic Information About Yellow Sac Spider: Questions and Answers

There are thousands of various spiders which may invade human dwellings, and yellow sac spider infestation appears to be one of the most widespread problems in many European and Asian countries. This species is not dangerous for people, but you should know how to identify this insect and suppress infestation, if required.

What It Looks Like?

It is quite easy to differ this insect from others: looking at pictures you will see that it has pale-brown body with yellow back part. Fangs and tips of legs are dark brown. Its size is about 5-10 mm (or ¼ of inch), equal for both females and males.

yellow sac spider

Its size is about 5-10 mm.

Where Does It Live?

Cheiracanthium is found in many countries of Europe and Asia, Canada, African regions and Argentina. This species usually live outside houses, preferring to make nests in leaves, among trash, or piles of branches and other debris. The insect makes tubular nets where it rests during daytime, leaves egg sacs and eats prey. When fall comes and it gets colder, this species finds shelter in houses, and yellow sac spider web is often found in corners and under ceiling. This is how infestation begins.

What Do They Eat?

In general, this species hunts other spiders and insects, and uses webs to catch them. During mating period, males get nutriment for females caring about eggs.


The insect makes tubular nets where it rests during daytime.

Is It Harmful for Humans?

Is yellow sac spider dangerous for people? No, it is quite small and non-aggressive, preferring to run away from threat rather than attack. Since this is a nighttime hunter, it may stuck into bed sheets and accidentally bite a person when being harassed. But even if such insect attacks, a person will not suffer a lot. Their bites may have the following symptoms:

  • skin inflammation, redness and slight swelling;
  • nausea;
  • pain in affected area;
  • itchiness;
  • fever;
  • fatigue and malaise;
  • muscle cramps.

It is quite small and non-aggressiv.

Yellow Sac Spider Bite Treatment

First you need to identify the bite: it looks like a small red spot (2-4 mm), but its size may depend on allergic reaction which may or may not develop in different people. If you have been attacked by this insect, do not panic: it is not poisonous. Just a few actions will provide reliable protection against infection. Wash the affected area with tap water and soap, and, if necessary, apply some ointment to relief skin irritation and itching. Remedies against allergy may also help.

Cheiracanthium is a relatively harmless creature, so don’t be afraid of any contact with it. Keep an eye out for webs in your house, and it won’t ever disturb you.

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1 Comment
  1. This article is dangerous misinformation. Yellow Sac spiders ARE venomous and you SHOULD avoid contact with them at all times. Look at pretty much every other website about Yellow Sacs and they will tell you this. Their bites are often mistaken for Brown Recluse bites because their venom causes very similar effects, including an open necrotic wound in some people, but less severe than a Brown Recluse bite. I’ve been bitten before. It’s not a “relatively harmless creature”. It’s irresponsible of you to tell people they shouldn’t be afraid to touch them when they can cause these types of symptoms. Just because the venom isn’t deadly doesn’t mean they’re harmless. Please edit your article, you’re causing people to risk their own health!

    If you think you may have been bitten, do not look for just “a small red spot (2-4 mm)” unless the bite just happened. It only looks like that in the beginning. Usually by the time most people notice the bite, it has grown into a painful, itchy, much larger red or purple spot surrounded by a ring of red swollen skin, or is an open hole with fluid coming out, in which case you need to be careful as you’re at risk of infection and it can take weeks to heal. That doesn’t happen to everyone but it definitely can and you should contact your doctor right away if you see this. You don’t need to go to a hospital though.

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