Common House Spider Bite: Is it Poisonous? Debunking Myths & Facts

House spiders are common indoor companions that we encounter frequently. These eight-legged creatures often spark fear and concern, especially when it comes to the potential danger of their bites. However, it’s important to know that not all spider bites are poisonous and many house spiders are unlikely to cause major problems for humans.

The American house spider is a typical cobweb spider that can be found lurking indoors. Interestingly, this spider is relatively harmless and often incapable of biting humans, even when provoked. While spider bites can induce various symptoms, ranging from itching to severe pain, bites from common house spiders are rarely a significant cause for concern.

Venomous spiders, such as the black widow and brown recluse, do pose a risk to both outdoor and indoor workers. However, these spiders are less common and require a level of caution that goes beyond what’s necessary for the average house spider. So, while it’s essential to stay vigilant for dangerous spiders, rest assured that most common house spiders are non-threatening in terms of their bites.

Common House Spider Bite

Identifying the Bite

A common house spider bite can be identified by its appearance. The bite may have:

  • Redness
  • Small swelling
  • No significant pain or harmful effects

Associated Symptoms

Symptoms associated with common house spider bites are generally mild or non-existent. However, some individuals might experience:

  • Itching or rash
  • Slight pain or discomfort

To summarize, common house spider bites are not poisonous or dangerous, and symptoms are typically mild or non-existent. These bites tend to cause redness and minor swelling, but should not be a cause for concern.

Is It Poisonous?

Venoms of Common House Spiders

Common house spiders are generally not considered venomous. Although their bites may cause minor symptoms such as itching or rash, they are mostly harmless to humans and have small amounts of venom. For example, the American house spider is a typical cobweb spider found indoors, which is grayish to brownish and mostly harmless.

Venomous Spiders

  • Black widow spider
  • Brown recluse spider

Non-Venomous Spiders

  • Common house spider
  • American house spider

Risk of Venomous Spiders

However, there are two dangerous venomous spiders in the United States: the black widow spider and the brown recluse spider1. Their bites can cause severe symptoms and, in rare cases, even death2.

Spider Color Markings Symptoms
Black Widow Shiny black Red hourglass Pain, muscle cramps, sweating, nausea
Brown Recluse Light brown Violin shape Skin damage, necrosis, fever, chills

It is essential to seek medical attention if you believe you have been bitten by either a black widow or brown recluse spider.

Nonetheless, spider bites are relatively rare, so the risk of encountering a venomous spider is quite low3. Keep in mind that most spiders, such as common or American house spiders, are not dangerous and may even help control other pests in your home.

Symptoms of Spider Bites

Mild Symptoms

Common house spider bites are usually not poisonous and often result in mild symptoms. These can include:

  • Itching or rash: A minor irritation may occur at the site of the bite.
  • Red bump: The bite may appear as a small, red bump on the skin, similar to a mosquito bite.
  • Pain: Some mild pain might be experienced around the bite area.

Severe Symptoms

Although house spider bites are generally harmless, some individuals may experience more severe reactions due to other factors such as an allergy. In rare cases, these severe symptoms can include:

  • Nausea and vomiting: Feeling nauseous and potentially vomiting.
  • Headache: Experiencing a headache after being bitten.
  • Fever and chills: A high temperature and shivering can be signs of a more severe reaction.
  • Difficulty breathing and weakness: The most concerning symptoms include trouble breathing and feeling weak overall.

While house spider bites are usually not a cause for concern, it is still crucial to monitor the symptoms and seek medical treatment if they become severe. Moreover, it’s worth noting that other venomous spiders, like the brown recluse and black widow, have bite symptoms that could be much more severe. Here’s a comparison table of the mild and severe symptoms:

Mild Symptoms Severe Symptoms
Itching Nausea
Red bump Vomiting
Mild pain Headache
Fever
Chills
Difficulty breathing
Weakness

Treatment for Spider Bites

Home Remedies

If you have been bitten by a common house spider, it’s important to know that their bites are usually not poisonous. However, you should still treat the bite to reduce discomfort and avoid infections. Start by:

  • Cleaning the area: Wash the bite with soap and water to clean the wound and remove any possible bacteria.
  • Using an ice pack: Applying ice to the bite can help reduce swelling, pain, and inflammation. For example, you can use a bag of frozen peas wrapped in a towel as an ice pack.
  • Taking over-the-counter medications: Pain relievers like ibuprofen or acetaminophen can help alleviate pain, while antihistamines can reduce itching and swelling.

It’s essential to monitor the bite for any signs of infection or an allergic reaction. If you notice the following symptoms, consult a medical professional immediately:

  • Redness and swelling that do not improve after a few days
  • Pus or discharge from the bite
  • Fever or chills
  • Difficulty breathing or swallowing

When to Seek Medical Attention

In some cases, a spider bite might require more than just home remedies. It’s crucial to seek medical attention if:

  • You suspect the spider is dangerous or poisonous like a brown recluse or black widow.
  • Symptoms worsen, or you experience numbness, intense pain, or lesions around the bite area.
  • There’s a risk of anaphylaxis, a severe, life-threatening allergic reaction.

When seeking medical attention, it’s helpful to identify the spider if possible. This information will help healthcare professionals decide whether further treatment, like antibiotics or hospitalization, is necessary. Additionally, if spiders are a recurring issue in your home, you might need to consider contacting a pest control service to help manage the situation.

Prevention of Spider Bites

Reducing Spider Presence in Your Home

  • Keep your home clutter-free: Regularly clean and organize your home, paying special attention to corners, curtains, and other areas where spiders might hide.
  • Pest control: Regularly inspect your home for signs of spider infestation and take necessary pest control measures, like using sticky traps or chemical treatments.

Personal Protective Measures

When handling items in storage spaces or areas with a potential spider presence, take the following precautions:

  • Wear a hat and long sleeves: Covering your head and arms reduces the chances of spider bites on exposed skin.
  • Be cautious: Always check items before picking them up, especially if they have been stored in dark, undisturbed spaces.

Common House Spider vs. Venomous Spider

Common House Spider Venomous Spider
Poisonous? No Yes
Location North America Varies
Necrosis Not caused Can cause
Joint pain Unlikely Possible

It’s worth mentioning that although common house spiders are not poisonous, certain venomous spiders like the brown recluse can be found in some areas of North America. Their bites can result in necrosis and joint pain. However, these spiders are rare, and most spider encounters in your home are with harmless species. By following the prevention tips mentioned above, you can minimize the risk of spider bites and keep your home spider-free.

Footnotes

  1. Common House Spider – Penn State Extension

  2. Symptoms of Venomous Spider Bites | NIOSH | CDC

  3. Diagnosing Mysterious “Bug Bites” – Insects in the City

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Common House Spider

 

Subject: Possible Brown Widow in Massachusetts?
Location: Great Barrington, Massachusetts.
July 7, 2012 12:56 pm
I’m not good with spiders, so she might just be another run-of-the-mill orbweaver. She just seemed a little different than the rest; her longer legs and her oddly marked abdomen is what caught my eye.
I saw she had babies (of course I thought they were the cutest things in the world), and I tried to take a picture the best I could. She was up in the corner, so I couldn’t get different angles. It’s a bit blurry, because I had my telephoto lens on.
Can you bug guys tell me what she is? Thanks!
Signature: -Terra

Common House Spider with egg sacs and spiderlings

Hi Terra,
Like the Brown Widow, this Common House Spider, Parasteatoda tepidariorum, is in the Cobweb Spider, family Theridiidae, but unlike the Widows, it is not considered to be dangerous.

Letter 2 – Cobweb Spider and Nephila clavipes

 

Hi.
Spiders, in general, freak me out. Your page makes me squirm and squint. I could use some help identifying a spider I found in abundance in my garage. The brown spider was with a dozen of his buddies… and dozens of eggs. They took over some shelves we had in our garage. I’m an over-protective new parent. Should this spider concern me? I also attached a spider that almost made my hair turn white. My wife and I came across it hiking in BVI. Is that thing poisonous?
Thanks
Scott

Hi Scott,
The brown spider in your home is Theridion tepidariorum, the most common of all house spiders. They spin a tangled maze of threads in the corners of neglected rooms. They are sedentary, spin webs to catch prey and to place their egg sacs. Off all the spiders that inhabit our dwellings, this is the most familiar, so it is sometimes called the Domestic Spider. It is exceedingly variable in color and markings. The female is larger. They are harmless.
The frightening spider from BVI (where is that?) is a silk spider called Nephila clavipes. They build enormous strong webs. They occur in the tropics and the American South. Your photo is the female which is about 100 times the size of the diminutive male. They may bite, but are relatively harmless. They are sometimes called Banana Spiders, but that is a common name used on Giant Crab Spiders as well.


Correction:  May 21, 2014
Just a few weeks shy of the tenth anniversary of this posting, we received a comment from Kalandria correcting our identification and indicating that the Cobweb Spider is
Steatoda triangulosa which we verified on BugGuide.

Letter 3 – Domestic Spider

 

Hello!
I have been looking through the spiders on your site, and believe my house is being overtaken by the jewelled araneus? I am sending pictures along, and the only reason I am not sure, is by your description of the web and breeding times. These spiders love the windows on our house, (eating moths, like you mentioned) but the webs are fairly small and quite messy. Not very "orb" like. They have stretched over large areas in some areas, like in my husband’s garage, from an engine stand to the bench. It ends up being almost hammock-like. Also, right now, almost everyone I have seen has about 3 egg sacks, some of which are "hatching" already. This doesn’t seem to match up with your description of them doing so in fall.
We’re not very worried about them, as they are adept bug killers. We live in Charles County, MD and we’re kind of out in the woods. We see plenty of different spiders! I have enclosed a picture of an adult female with egg sack, and the second is a younger one. I would appreciate your input, and would also like to know if having as many as we do is a problem. (they’re everywhere!!) Thanks for you time! (they also don’t seem to mind being in close proximity of each other)
Sincerely,
Debra

Hi Debra,
You have a Domestic Spider, Theridion tepidariorum. Comstock writes: “Of all the spiders that inhabit our dwellings, this is the most familiar, and consequently best merits the title of the Domestic Spider. Its tangle of threads can be found in almost any neglected room, throughout the length and breadth of our country; and the species is not limited to our country for it is almost a cosmopolite. This is an exceedingly variable species in colour and markings. … The egg-sacs are brownish and pear-shaped with a dense outer coat. They are suspended in the web, and several of them are made by one spider.”

Letter 4 – Domestic Spider with Eggsac

 

please help identify this spider before her egg sac hatches!!!!
i recently noticed this spider in my garage, flanked by not one, but two egg sacs. i’m not too keen on having one (poisonous??) spider around, but the thought of all those little baby spiders running around is too much to handle!! can you please tell me what kind of spider this is?? she’s not all that big, round, and definitely shiny. thanks for the site, it rocks!!!
dana

Hi Dana,
Even if you got rid of your Domestic Spider, Theridion tepidariorum, and her eggs, her relatives would most assuredly move in. The Domestic Spider earns her common name. Comstock writes: “Of all the spiders that inhabit our dwellings this is the most familiar, and consequently best merits the title of the Domestic Spider. The tangle of threads can be found in almost any neglected room, throughout the length and breadth of our country; and the species is not limited to our country for it is almost a cosmopolite. This is an exceedingly variable species in colour and markings.” Your specimen has very definite marking unlike any we have previously seen. While all spiders possess venom, the Domestic Spider is no threat to humans. Just let her raise her family and they will help control true pests that enter you home.

Letter 5 – Female Domestic Spider

 

What is this guy?
A colony of these spiders has set up shop in a crawlspace under a cottage on the Bruce Peninsula in Ontario, and seem to be wintering over. It is a damp and cold area (just above freezing). There are perhaps 6 of them, most having egg sacks near them. I haven’t seen anything like them before!
Thanks
Andrew

Hi Andrew,
Your gal is a female Domestic Spider, also commonly called a House Spider, Achaearanea tepidariorum. These small harmless Comb-Footed Spiders are common around the home, hence their common name. Your photo nicely illustrates the large and bulbous abdomen with its cream coloration and dark blotches. They spin irregular webs.

Letter 6 – Probably Domestic Spider

 

What type of spider is this?
This was found under a large plastic child’s outdoor slide. It had spun a web approximately 12 inches across overnight. The bottom of the slide had been sprayed the previous evening. This is the best photo of that I can produce. Thank you for your assistance and your web site.
Vern Nusunginya
Kenai, Alaska

Hi Vern,
It looks like a Domestic Spider, Theridion or Achaearanea tepidariorum. It is one of the commonest spiders that is found in homes, hence it earns the common name Domestic Spider.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Common House Spider

 

Subject: Possible Brown Widow in Massachusetts?
Location: Great Barrington, Massachusetts.
July 7, 2012 12:56 pm
I’m not good with spiders, so she might just be another run-of-the-mill orbweaver. She just seemed a little different than the rest; her longer legs and her oddly marked abdomen is what caught my eye.
I saw she had babies (of course I thought they were the cutest things in the world), and I tried to take a picture the best I could. She was up in the corner, so I couldn’t get different angles. It’s a bit blurry, because I had my telephoto lens on.
Can you bug guys tell me what she is? Thanks!
Signature: -Terra

Common House Spider with egg sacs and spiderlings

Hi Terra,
Like the Brown Widow, this Common House Spider, Parasteatoda tepidariorum, is in the Cobweb Spider, family Theridiidae, but unlike the Widows, it is not considered to be dangerous.

Letter 2 – Cobweb Spider and Nephila clavipes

 

Hi.
Spiders, in general, freak me out. Your page makes me squirm and squint. I could use some help identifying a spider I found in abundance in my garage. The brown spider was with a dozen of his buddies… and dozens of eggs. They took over some shelves we had in our garage. I’m an over-protective new parent. Should this spider concern me? I also attached a spider that almost made my hair turn white. My wife and I came across it hiking in BVI. Is that thing poisonous?
Thanks
Scott

Hi Scott,
The brown spider in your home is Theridion tepidariorum, the most common of all house spiders. They spin a tangled maze of threads in the corners of neglected rooms. They are sedentary, spin webs to catch prey and to place their egg sacs. Off all the spiders that inhabit our dwellings, this is the most familiar, so it is sometimes called the Domestic Spider. It is exceedingly variable in color and markings. The female is larger. They are harmless.
The frightening spider from BVI (where is that?) is a silk spider called Nephila clavipes. They build enormous strong webs. They occur in the tropics and the American South. Your photo is the female which is about 100 times the size of the diminutive male. They may bite, but are relatively harmless. They are sometimes called Banana Spiders, but that is a common name used on Giant Crab Spiders as well.


Correction:  May 21, 2014
Just a few weeks shy of the tenth anniversary of this posting, we received a comment from Kalandria correcting our identification and indicating that the Cobweb Spider is
Steatoda triangulosa which we verified on BugGuide.

Letter 3 – Domestic Spider

 

Hello!
I have been looking through the spiders on your site, and believe my house is being overtaken by the jewelled araneus? I am sending pictures along, and the only reason I am not sure, is by your description of the web and breeding times. These spiders love the windows on our house, (eating moths, like you mentioned) but the webs are fairly small and quite messy. Not very "orb" like. They have stretched over large areas in some areas, like in my husband’s garage, from an engine stand to the bench. It ends up being almost hammock-like. Also, right now, almost everyone I have seen has about 3 egg sacks, some of which are "hatching" already. This doesn’t seem to match up with your description of them doing so in fall.
We’re not very worried about them, as they are adept bug killers. We live in Charles County, MD and we’re kind of out in the woods. We see plenty of different spiders! I have enclosed a picture of an adult female with egg sack, and the second is a younger one. I would appreciate your input, and would also like to know if having as many as we do is a problem. (they’re everywhere!!) Thanks for you time! (they also don’t seem to mind being in close proximity of each other)
Sincerely,
Debra

Hi Debra,
You have a Domestic Spider, Theridion tepidariorum. Comstock writes: “Of all the spiders that inhabit our dwellings, this is the most familiar, and consequently best merits the title of the Domestic Spider. Its tangle of threads can be found in almost any neglected room, throughout the length and breadth of our country; and the species is not limited to our country for it is almost a cosmopolite. This is an exceedingly variable species in colour and markings. … The egg-sacs are brownish and pear-shaped with a dense outer coat. They are suspended in the web, and several of them are made by one spider.”

Letter 4 – Domestic Spider with Eggsac

 

please help identify this spider before her egg sac hatches!!!!
i recently noticed this spider in my garage, flanked by not one, but two egg sacs. i’m not too keen on having one (poisonous??) spider around, but the thought of all those little baby spiders running around is too much to handle!! can you please tell me what kind of spider this is?? she’s not all that big, round, and definitely shiny. thanks for the site, it rocks!!!
dana

Hi Dana,
Even if you got rid of your Domestic Spider, Theridion tepidariorum, and her eggs, her relatives would most assuredly move in. The Domestic Spider earns her common name. Comstock writes: “Of all the spiders that inhabit our dwellings this is the most familiar, and consequently best merits the title of the Domestic Spider. The tangle of threads can be found in almost any neglected room, throughout the length and breadth of our country; and the species is not limited to our country for it is almost a cosmopolite. This is an exceedingly variable species in colour and markings.” Your specimen has very definite marking unlike any we have previously seen. While all spiders possess venom, the Domestic Spider is no threat to humans. Just let her raise her family and they will help control true pests that enter you home.

Letter 5 – Female Domestic Spider

 

What is this guy?
A colony of these spiders has set up shop in a crawlspace under a cottage on the Bruce Peninsula in Ontario, and seem to be wintering over. It is a damp and cold area (just above freezing). There are perhaps 6 of them, most having egg sacks near them. I haven’t seen anything like them before!
Thanks
Andrew

Hi Andrew,
Your gal is a female Domestic Spider, also commonly called a House Spider, Achaearanea tepidariorum. These small harmless Comb-Footed Spiders are common around the home, hence their common name. Your photo nicely illustrates the large and bulbous abdomen with its cream coloration and dark blotches. They spin irregular webs.

Letter 6 – Probably Domestic Spider

 

What type of spider is this?
This was found under a large plastic child’s outdoor slide. It had spun a web approximately 12 inches across overnight. The bottom of the slide had been sprayed the previous evening. This is the best photo of that I can produce. Thank you for your assistance and your web site.
Vern Nusunginya
Kenai, Alaska

Hi Vern,
It looks like a Domestic Spider, Theridion or Achaearanea tepidariorum. It is one of the commonest spiders that is found in homes, hence it earns the common name Domestic Spider.

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

8 thoughts on “Common House Spider Bite: Is it Poisonous? Debunking Myths & Facts”

  1. Is the house spidee harmful? Do they bite? I just found one behind my bed, with a few egg sacs on my bed post. I am really freakes out, checked behind all my daughter’s furniture too.

    Reply
  2. So I recently found out that my garage has quite few of these spiders and I’ve seen several of their spiderlings also… is it possible I have an infestation? Should I call an exterminator to come out to check into it or just leave them be? We use the garage daily as I park my suv and next to mine is my husband’s suv which he is in the process of working on fixing up. I’ve noticed several spiders/spiderlings up underneath the chassis and in/along the tires/tire tread of my husband’s suv that doesn’t move as well as along the edges of the garage where random items lay, such as a work bench for example. I can easily spot the spider’s homes’ by the accumulation of rolly polly shells that collect in a pile on the floor. My husband recently sprayed for the rolly polly infestation that we had outside and it seem as though my husband took away the spider’s main food supply and since that’s happened they’re starting to come out of the wood works to where I’m seeing them everywhere! What should I do? PLEASE HELP!

    Reply
  3. I’m in Burleson, Texas (south of Fort Worth, Texas)… I forgot to include that in my previous comment/post/question. Thanks!

    Reply
  4. Okay, so what do you recommend I do to rid my garage of them? Or are they a good spider to have around to keep all the other bugs out? I’ve done a little research and they seem to be harmless and eat all the bugs, but I’m terrified that they’re going to come into my living areas and with my OCD, I can’t be having that… especially around my 2y and 9mo old children. Thanks so much!!

    Reply

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