Yellow sac spiders are small, agile creatures that can sometimes find their way into our homes. These spiders can be yellow, white, or even greenish, with their legs and upper body being darker than their abdomen. Mainly garden-dwellers during the warm season, they can make their way indoors in the fall, and their bites can cause discomfort when they get trapped against a person’s skin in clothing or bedding source.
Dealing with these unwelcome guests may seem challenging, but there are several methods to effectively manage and prevent their presence. In this article, we will provide practical tips on how to get rid of yellow sac spiders, ensuring a more comfortable living environment. From home maintenance to natural deterrents, these simple steps will help you keep your home spider-free.
Identifying Yellow Sac Spiders
Yellow sac spiders have a distinctive appearance, making them easy to identify. They have two main species in the United States: Cheiracanthium inclusum and Cheiracanthium mildei.
Yellow sac spiders are small to medium-sized spiders, ranging from 1/4 to 3/8 inches in length.
These spiders can vary in color from pale yellow to light green or beige, with a darker colored stripe or line running down their backs.
Yellow sac spiders have eight legs, with the front pair being longer than the rest. This characteristic helps them move quickly and climb efficiently.
United States Species: Cheiracanthium Inclusum and Cheiracanthium Mildei
- Cheiracanthium Inclusum: Primarily found outdoors in gardens, they often enter homes during autumn. Their egg sacs can be found on the undersides of leaves or other foliage.
- Cheiracanthium Mildei: Commonly found indoors, especially in corners, behind shelves, and on walls or ceilings. They spin small silken sacs as their resting place.
Comparing the two species:
|Feature||Cheiracanthium Inclusum||Cheiracanthium Mildei|
|Habitat||Outdoors, gardens||Indoors, homes|
|Egg Sac Location||Under leaves, foliage||Corners, walls, ceilings|
Both species are active hunters and don’t rely on webs to catch their prey. As a result, they sometimes bite humans when they become trapped between skin and clothing or bedding.
Yellow Sac Spider Habitats and Behaviors
Yellow sac spiders can be found in various areas of a home, such as:
- Ceilings, walls, and corners: They are known to spin a silken sac web near corners of ceilings and walls.
- Attics and basements: They may reside in attics or basements due to the presence of clutter where they can hide.
- Bed: They may accidentally encounter humans in bed when they become trapped between skin and sheets.
Yellow sac spiders can also be found in several outdoor areas:
- Gardens, trees, and woodpiles: Some species choose to deposit their eggs on the undersides of leaves or other foliage.
- Vegetation: They may reside near vegetation seeking prey or protection.
- Cold and warm environments: Yellow sac spiders adapt to both cold and warm climates, as they can be found in various regions.
Diet and Prey
Yellow sac spiders have a diverse diet, primarily consisting of:
- Insects and other arthropods
- Feeding on dead and decaying arthropods
Prey Hunting Techniques
- Active hunters: They search for prey instead of capturing it within a web, as mentioned by the College of Agriculture.
- Nighttime activity: Yellow sac spiders are primarily nocturnal and are more likely to be encountered during the night when they hunt for prey.
Bite and Venom
Yellow sac spider bites may cause:
- Initial pain similar to a bee sting
- Redness and swelling
These spiders usually bite when they get trapped between a person’s skin and clothing or bedding 1.
Yellow sac spider venom is not considered life-threatening. It can cause the following symptoms at the bite site:
- Pain and redness
- Swelling and itchiness
Comparison with Brown Recluse Spider Bite
Let’s compare the bites of Yellow sac spiders and Brown recluse spiders:
|Feature||Yellow Sac Spider Bite||Brown Recluse Spider Bite|
|Pain||Moderate||Mild to severe|
|Necrosis (tissue damage)||Rare||Common|
|Severity of symptoms||Less severe||More severe|
|Medical attention requirement||Rarely||Often|
Treatment and Medical Attention
If bitten by a yellow sac spider, you can try the following at home:
- Clean the bite area with soap and water
- Apply an ice pack to reduce swelling
- Use over-the-counter pain relievers and anti-inflammatory medications
Seek medical attention if symptoms worsen, such as increased pain or an allergic reaction.
Prevention and Control Methods
Sealing Gaps and Cracks
To prevent yellow sac spiders from entering your home, seal gaps and cracks around doors, windows, and the foundation. Examples of common entry points include:
- Window frame gaps
- Door frame gaps
- Cracks in foundation
Sealing these areas not only helps with spider control but also reduces energy consumption by improving insulation.
Cleaning and Clutter Management
Maintain a clean and clutter-free environment to discourage spider infestations. Regular cleaning activities to consider are:
- Dusting ceiling corners and walls
- Vacuuming windowsills and floors
- Removing leaf piles and old vegetation near the foundation
These cleaning practices also help control other pests like ants and flies.
Pest Control Services
Hire professional pest control services for a comprehensive solution to yellow sac spiders. Professionals can identify risks, apply targeted treatments, and provide recommendations for ongoing prevention.
Natural Remedies and Essential Oils
Yellow sac spiders dislike certain natural scents, such as peppermint oil and vinegar. Make a repellent spray by mixing:
- 10-15 drops of peppermint oil
- 1 cup of water
- 1/4 cup of vinegar
Spray the mixture in corners, around windows, and near garbage areas to deter spiders.
Traps and Vacuum Techniques
Use spider traps and vacuum cleaners to capture and remove yellow sac spiders. Place traps in locations where spiders commonly retreat, such as:
- Ceiling corners
- Behind furniture
- Near entry points
Regularly vacuum floors, walls, and ceilings to remove spiders, egg sacs, and webs.
Here’s a comparison of spider control methods:
|Sealing Gaps and Cracks||Deters spider entry, saves energy||Requires regular maintenance|
|Cleaning and Clutter||Prevents infestations from multiple pests||Time-consuming|
|Pest Control Service||Expert assistance and comprehensive solutions||Costly|
|Natural Remedies & Essential Oils||Chemical-free and eco-friendly||May require frequent application|
|Traps and Vacuum Techniques||Direct removal of spiders and webs||Needs consistent monitoring & work|
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 – Yellow Sac Spider
What kind of spider is this?
December 17, 2009
I keep finding these little spiders in my house, specifically in my bathroom. They seem to like to be on the ceiling above the shower and I always freak out when I see one while I’m in there because I don’t know what kind of spider it is and whether or not they are of any danger to me. They are usually about the size of a nickel and very pale in color. Can you tell me what kind of spider this is and a little bit about it please?
This species that has been introduced from the Mediterranean, Cheiracanthium mildei, is known by several common names, including Yellow Sac Spider, Black Footed Spider, and Cream House Spider. The spider will bite, most often when it is trapped in clothing. It was once believed that the bite of the Yellow Sac Spider was associated with blisters and lesions, but this has not proven to be the case, and the species should be removed from the medical concern list according to BugGuide. You may read more on the ASTMH website of the American Journal of Tropical Medicine and Hygiene.
Letter 2 – Yellow Sac Spider
Subject: Unexpected Roomates
Geographic location of the bug: Ventura, Ca
Time: 10:01 PM EDT
Your letter to the bugman: Dearest Bugman,
I recently changed my residence and have noticed quite a few additional spiders in my new space. I assumed that the majority of what I see are ‘daddy long legs’ (please excuse my potential misuse of this street name for what I believe are harmless/helpful creatures that pose no threat to the likes of me). However, today I spotted something totally different. Mostly ‘white’/ translucent with what appear to be ‘black shoes’ on each foot. Please let me know who my new roommate is.
How you want your letter signed: Melanie on the Irish Chain
The “daddy long legs” that you mentioned are most likely Long Bodied Cellar Spiders which we identified for you in the past. Your current request appears to be a Yellow Sac Spider or Black Footed Spider, Cheiracanthium mildei, which is pictured on BugGuide where it states: “More often found inside man-made structures” and “Sac spiders are classified as hunting spiders. These spiders are very active at night and will emerge from their day resting sacs to run along walls and ceilings in pursuit of prey. If startled, they drop down on draglines and scurry away! Imported from Europe in the 1940s.” This is not considered a dangerous species to humans, but BugGuide does note: “Yellow sac spider bites occur most frequently when the very defensive spider is trapped in clothing.” Charles Hogue calls this species a Cream House Spider.
I tried to respond via the website but wasn’t able to figure it out.
My response was going to be something to the tune of… if getting trapped in clothing is problematic for these spiders than I will plan on wearing much less when I am at home.