The Spiders in your House - The Yellow Sac Spider

A close look at Cheiracanthium mildei, the Yellow Sac Spider, how it will behave (and affect you) living in your house, the bite and the venom, and other fascinating stuff.

All photos and video are my own, UNLESS OTHERWISE CREDITED.

Note that I am an amateur, not a professional. If you think I have made a mistake, let me know in the comments!

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REFERENCES:

Vetter RS, Isbister GK, Bush SP, Boutin LJ. Verified bites by yellow sac spiders (genus Cheiracanthium) in the United States and Australia: where is the necrosis?. Am J Trop Med Hyg. 2006;74(6):1043-1048.

Isbister GK, Whyte IM. (2004). Suspected white-tail spider bite and necrotic ulcers. Internal Medicine Journal (34), 38-44.

Spielman A, Levi HW. (1970). Probable envenomation by Chiracanthium mildei; a spider found in houses. Am J Trop Med Hyg (19), 729-732.

Taylor RM, Bradley RA. (2009). Plant nectar increases survival, molting, and foraging in two foliage wandering spiders. The Journal of Arachnology (37), 232-237.

Schmalhofer VR, Reineke P, Roslender C. 2016, April 8. Testing an urban myth: do spiders really “love” the smell of gasoline? Poster session presented at IUPUI Research Day 2016, Indianapolis, Indiana.

Krell FT, Kramer F. (1998). Chemical attraction of crab spiders (araneae, thomisidae) to a flower fragrance component. The Journal of Arachnology (26), 117-119.

Amalin D, Reiskind J, Pena JE, McSorley R. (2001). Predatory behavior of three species of sac spiders attacking citrus leafminer. The Journal of Arachnology (29), 72-81.

Isbister GK. (2004). Necrotic arachnidism: the mythology of a modern plague. The Lancet 364(9433), 549-553.

Divito SJ, Haught JM, English JC, Ferris LK. An extensive case of dermonecrotic arachnidism. J Clin Aesthet Dermatol. 2009 Sep;2(9):40-3. PMID: 20729958; PMCID: PMC2923970.

Papini, Roberto. (2011). Documented bites by a yellow sac spider (Cheiracanthium punctorium) in Italy: A case report. Journal of Venomous Animals and Toxins including Tropical Diseases. 18. 349-354. 10.1590/S1678-91992012000300014.

Rose, S. (2022). Spiders of North America. Princeton University Press

Land MF. (1985). The Morphology and Optics of Spider Eyes. In F.G Barth (ed.), Neurobiology of Arachnids (pp. 53-78). Springer-Verlag.

[joshstarkey]

I never expected to be up at 2am watching a man harass spiders with cheese on a stick, but I'm glad I'm here

[blondyh]

I get these spiders in my bathroom every year. I finally decided to look up what they were and was briefly horrified to hear about their agressive and necrotizing bites. Then I thought back to all the times they've accidentally gotten in my hair or down my shirt and nothing has happened and figured I had either mis-identified them or the tales of their horror were overstated.

You pretending to be an upset teacher over Wikipedia cracked me up.

[postyoda]

Holy, you're a meticulous perfectionist, I loved that you tried to do your own observations and experiments, rummaged through literature and contacted other researchers. Solid stuff through and through.

[walmart_is_a_cult]

You had me at "cute black toesies". Ms YellowSac now has a spooky story for the kids about the time she battled a Cheese Monster.

[markrichards]

I've actually been bitten by them a few times, put my arm down on one while playing cards once, then a couple times cleaning the basement. It was less painful than a bee sting, but the bite became a very itchy, raised, red welt. It cleared up within a day. I don't kill them. I move them to the back porch. They get rid of other bugs.
BTW I user to work in the ER. The necrosis from spider bites I've seen, generally isn't a spreading necrosis, rather localized to a small area at the site of the bite.

[VoodooLily]

I got tired of being afraid of spiders. Ignorance breeds fear, so I'm learning about them. Thank you for sharing this info!
When traveling last summer our RV picked up quite a few of these guys.

[chadb]

Thanks for sharing - I was bitten by one of these, my only spider bite that I knew what it was...I tried to scare it off with my barefoot toe. Bad idea, it bit me. Stung no more than yellow jacket, no necrosis, slight swelling that subsided with the pain over the next 30 minutes or so. Within an hour all symptoms were gone. Still a healthy respect though.

[arcadeunskilled]

The hairs on their feet are important for chemosensation and also climbing grip, so my nonacademic guess is that keeping the feets properly groomed is particularly important for active hunters who climb a lot.

[MyRegularNameWasTaken]

6:27 with the absolutely perfect delivery of "... a screen" is one of the greatest moments in cinematic history, possibly ever.

[shanevandiver]

As a former landscaper, I used to encounter these guys all the time. I was only ever bitten one time and that was because it got trapped in my glove where it is loose around the wrist.
All that happened was the bite area turned into a pustule that was moderately painful if it was disturbed. Within a week, it was cleared with no other issues. These spiders are not aggressive, and their venom is more of an irritant than anything. Still you need to wash the bite to prevent any sort of bacterial infection.

[WayraHyena]

As someone who loves having spiders in and around the house, I love your rating/reviewing at the end. "If you like surprises but don't like messes, this is the spider for you! Very polite and tidy" it got a great giggle out of me because it sounds like how I would talk to my arachnophobic friends.

[eldrichnemo]

This was suggested me to at random and immediately I sang along "the spiders in my car!" because I used to get yellow sac spiders in a 00s Toyota I owned. One time one sat placidly on my shoulder while driving a teen sibling around, another time I *felt* one sling from my head onto the sun visor because I could detect the pull of the silk tether, it was that strong, never felt anything like it before or again, just amazing stuff! I had no idea about the misinformation of WHY these spiders took interest in cars and still believed it to be gasoline-related, so I LOVE I learned the truth from your video! I can't wait to watch more. I love spiders and often wrangle them out of the reach of family and coworkers who aren't as arachnid-apologist as I. I've even taught my mom to catch and release them herself because over the years she understands it's important to keep them alive.

The rock in water is BRILLIANT! And the example of surface tension, wow!
EDIT: the upper right text in the aggression test. 🤣

[rou]

That shot of the spider slowly swaying on the water as chill as can be was absolutely priceless, thank you.

[SilentGloves]

Long-term certified arachnophobe here. Keep doing these! Lucas got me over my fear of jumping spiders, and since then, I've found that being able to identify spiders, knowing their behaviors, usefulness, and actual danger factor has been instrumental in me accepting these creatures, appreciating them, and I've even become somewhat fascinated by them. When I see a jumping spider on my house now, I'll stick out my hand and see if they'll hop onboard! I would have never imagined I would do such a thing. This is one of the best series I've seen in this regard. The one's that still give me the willies are what I call the "High-Speed Ground Hunter" variety.

[MakoWoman]

For years now I’ve been trying to convince my parents not to be scared of spiders, and your videos have finally done the trick! Love the research, love the video-work, great stuff!! 🙂

[shadowofcloud]

I'm so glad you made a video defending our little friends! I've been telling people for YEARS that the Yellow Sack Spiders are nothing to worry about.

[Catillia]

"Less wronger is more better" is quite possibly the best thing I've ever heard. I spent some time trying to defend spiders to a group of people just yesterday, I encouraged them to learn more about them because I think the fear most people have of spiders is due to a lack of knowledge. Thanks for this video, I can't wait to watch more of them!

[starra]

I love the fact that you just don't glean information from wikipedia, but actually do research and display what you found in an easy well informing structured way. Kudos to you! Subscribed.

[SydSny]

as a huge spider-enjoyer, i really love your content and how it works towards destigmatizing spiders. the focus on common household spiders especially feels very effective at this goal as well! keep up the good work!

[misteranderbro]

Despite living with these spiders for decades, I have never once heard that their bites "supposedly" cause necrosis. I thought it was common knowledge that they were relatively harmless unless provoked.

Excited for the future of this channel and a better understanding of our nightly protectors