black widow infestation!! help me not bomb the house...

We removed our DOOMmate about a month ago and realized we have a huge black widow infestation.  She lived in the basement and it was hard to get down there to check or maintain.  The black widows are/were babies and they are starting to make their way upstairs.  There are so many we can't just get rid of them by relocating or squashing.  The house is about 100 yrs old, so it has a lot of inviting nooks and crannies for the black widows to enjoy.  

This year has been particularly bad.  Even our unused vehicles are infested.  

Here's my dilemma: I never want to use toxic gick, but now I have a baby and an elderly kitty who i can't relocate temporarily (she's gone senile and might die from the confusion).  I have never had to deal with something that was more than a nuisance.  I am worried about all my animals, my kid, and us somehow coming into contact with these poor guys and having an unfortunate encounter.  Especially the baby and the chihuahua because they are so teeny!

Not only am i concerned about being bitten, but my primitive brain has also been working overtime to try to protect me, so anything that touches me is obviously a black widow.  I'm on high alert and it is exhausting.  

So far we are dusting with diatomaceous earth and spraying with neem oil.  And so far the upstairs population has been minimal and managed with relocation and/or squishing.  I just found a dead full grown one in the living room right next to our sitting area.  So shit has gotten real.

As it begins to get colder the problem will only escalate, so I am looking for an alternative to poisoning our home.  Maybe if we just triple our efforts, we will be ok?  

Any ideas are greatly appreciated and will most likely be attempted.  

I really hate the idea of a baby and small animal in this kind of situation. I'd  say to remove them from the house and then try to get the spiders out, having dealt with brown recluse infestations (they are tenacious besides being dangerous).

I do remember using boric acid for bug invasions years ago and it being really effective. It was sprinkled in lines around every nook and cranny of the house and as I remember it isn't toxic to humans so can be used inside kitchen cabinets etc.

Please be careful with this though. These critters don't play.

Indeed they do not!

Thanks for your suggestion!  I will definitely try out the boric acid.  I hadn't thought of that!

There are exterminator type companies that do heat treatments to buildings. The house has to stay around 120F for a few hours. From what I've heard this takes alot of preparation, making sure items are removed that would pose a hazard at those temperatures, as well as sealing things off well to ensure the correct temperatures are sustained in the entirety of the building. The siding was a tricky spot from a friends DIY, eventually successful, series of attempts at getting rid of bedbugs.

Hi S,
I am no spider expert, so please take this with a grain of salt. I too would feel safer with the baby out of the house, but I know that may no be an option. Here are some thoughts in no particular order.

I know many spiders will hide during the day, or at least with bright light. Maybe black widows do too? I would try leaving bright lights on more often.

Many spiders need/want hiding places due to this hiding during the day. De-clutter! (bonus, this will help with most household issues, including mice, rats, cockroaches, spiders, ants, etc). They all want places to hide and feel safe... give them fewer and they will not feel as comfortable. As a bonus, it will make it easier to see them. This may require getting some sealed containers and putting clothes and food and nicknacks into them for the time being. Don't leave stacks of things around.

Work on sealing up your basement. I don't believe black widows care for crumbs of people food, so you want to remove hiding places and entry way for the bugs that the black widows are looking for.

Perhaps consider setting up a "secure" room for the baby to spend the nights and good parts of the day? Remove most of the furniture, use caulking/spray foam/etc. on ALL cracks and openings. I have lived in old houses and I know how hard this is... which is why I'm suggesting you start with one room. Don't leave any food or any hiding places for any bugs or spiders. Combine that with some of the sprays and powders suggested, and that aught to reduce the chances of any spiders coming into that room.

Vacuum... I have used this successfully to help with a cave/house spider infestation. I know they are not poisonous, but I did not like the sheer numbers and having to wonder if they would fall on me in the shower or when I went into the basement. So I used a vacuum and sucked up all the ones I could find and their webs. It did not get them all, but it did reduce their numbers.

I don't remember the exact recipe, but my wife made up a spray that was fairly effective against all the kinds of spiders we had. I know it had vinegar, garlic, and some essential oils mixed in with water. She would spray it around the top of the rooms. It seemed to help for a while after that.

If all else fails, I would agree with the suggestion to call the professionals. I know people automatically assume an exterminator will use poison... and it will probably be the first suggestion, but many now do have safer and more natural alternatives. It might at least be worth a call.

j- i know that heat treatment does wonders for bed bugs, but I didn't know it would do the same for spiders.  I guess that makes sense.  I started looking for professionals who do this treatment in my area and so far no luck.  I don't trust myself to be able to do this effectively.  

Matt-  thank you for your suggestions! We have created a secure space, such as you mentioned, for us and the baby to sleep in.  These black widows have definitely instigated a "fall cleaning" of sorts.  We are de-cluttering and re evaluating the need of anything that doesn't have a home.   I have begun to look into more professional options that offer eco & baby safe options.  There are a couple in our area., so at least we have the option if our efforts do not prove to be fruitful in the next couple of days.  


I truly appreciate everyone's thoughtful responses and I am already feeling more prepared to squish this problem without the toxic gick!

Years ago I learned that the vinegar I used to clean my countertops also kills bugs.  I keep a spray bottle on my counter to clean and kill. I mix it 50/50 with vinegar and water.

Yes, it will kill black widow spiders. The acidity in the vinegar burns them on contact.

Anne Miller wrote:Years ago I learned that the vinegar I used to clean my countertops also kills bugs.  I keep a spray bottle on my counter to clean and kill. I mix it 50/50 with vinegar and water.

Yes, it will kill black widow spiders. The acidity in the vinegar burns them on contact.

This is wonderful!  We always have vinegar on hand for cleaning.  I'm really excited about this!  Thanks, Anne!

Wow, how scary.
We moved into a house that had been abandoned for a few years, and the wooden drop ceilings had sort of shrunken away from the walls, leaving cracks in the paneling. The first few nights we noticed that when the lights went off, the spiders dropped down. The cable guy refused to go up in the attic, telling me he saw so many brown recluses he couldn't even count them, and I figured we were in trouble. I had never dealt with poisonous spiders and had a small kid and I was terrified.

We did exactly what was described above with the "baby proof room"-- we used expanding foam to fill in every single open space in the ceiling. Then we proceeded to suit up and harrass the heck out of the spiders. They want a calm, undisturbed place to call home, and just running a broom over every surface, in every corner, under every thing every so often is enough to send them packing.

In our new house (concrete, no paneling, no ceiling gaps) we have them in the attic and notice that in certain seasons the spiders come in. We shopvac the heck out of everything, and use stinky stuff for cleaning surfaces where and when we do see them. Vinegar, alcohol, even kerosene is commonly used here when spiders are the issue. More important is getting underneath things (beds, chairs, sofas, cabinets, etc) and making sure they are not getting comfortable. The more you do this the more they will find it easier to just look for a quieter place to live.

In select areas, I have had luck with double sided sticky tape.

I live in an old house in-between a walnut and almond orchard in California, for almost 30 years.  I have lived and raised 4 children.  We have tons of black widows.   My son was bit two times a few years ago, but the symptoms don't match, so I have a feeling it was a wolf spider, or brow recluse.  Anyway the point is black widows are shy and want nothing to do with humans.  As long as you shake out shoes, and don't stick your hands in dark unseen places, you and your family will probably never get bit. I hate spiders, and understand your fear, but odds are besides freaking you out, they probably won't cause you any problems. Good luck

Jen Fulkerson wrote:I live in an old house in-between a walnut and almond orchard in California, for almost 30 years.  I have lived and raised 4 children.  We have tons of black widows.   My son was bit two times a few years ago, but the symptoms don't match, so I have a feeling it was a wolf spider, or brow recluse.  Anyway the point is black widows are shy and want nothing to do with humans.  As long as you shake out shoes, and don't stick your hands in dark unseen places, you and your family will probably never get bit. I hate spiders, and understand your fear, but odds are besides freaking you out, they probably won't cause you any problems. Good luck

Thank you for the reassurance.  I generally leave spiders alone because they have their place helping us out in their own way.  We like to say we have an accord with them (we don't kill them, they don't bite us).  However, I think when we had the baby all of our anxieties grew ten times bigger, haha!  Logically, I know they prefer to hide and be left alone, and even though the population of black widows boomed this year, you're right.  The likelihood of us getting bit is low.  The animals might have a bit higher chance, especially this time of year.  I think with the help of all the y'alls great permies minds out there we stand a chance to get what is going on under control.  

Jen Fulkerson wrote: As long as you shake out shoes, and don't stick your hands in dark unseen places

This is multiple-apple advice. Thank goodness we can learn new habits. We all learned right quick to shake out shoes and hanging towels/clothes, and to never fool around in spidery places without gloves. It's second nature now.

Have you considered having an ozone treatment done on your house? It's less nasty/persistent than insecticides.

Aside: If the spiders are doing that well, I wonder what they are feeding on. Hmm.

Douglas Alpenstock wrote:Have you considered having an ozone treatment done on your house? It's less nasty/persistent than insecticides.

Aside: If the spiders are doing that well, I wonder what they are feeding on. Hmm.

Right!  I am sure that my former roommate did not have the best habits when it came to pest control in an old house.  Plus there are too many points of entry to count.  some sections of our basement is still dirt floor.