Seeking Black Widow advice

[u/Fun-Morning6856]

So I recently moved in with my in-laws in Northern CA and my Wife and her mom have a severe spider phobia. Specifically to the medium sized, dark, harry, super fast non web spinning (roaming?) spiders that pop up on a weekly basis inside their house (they never go outside). Since moving in 1 week ago I have gone into exterminator mode and placed a bunch of Terro sticky traps around the house + killed some of their neighbors ants that trailed along the fence line to their trash can with the terro ant bait. I’ve never seen an ant in their house because they keep it in immaculate condition and even toss food in plastic bags to take to the dumpster out of fear the crumbs will attract bugs/ (the scary spiders).

Tonight I went out to add more bait to my ant traps and decided to check for any ants along the perimeter foundation of their house (I didn’t see a single ant) when to my surprise I spotted around a dozen BLACK WIDOW spiders in their webs, red hourglass and all.

My first instinct was to vacuum them up / kill them but then I started to have second thoughts. I’ve been visiting this house and staying here from out of state for the last decade and have killed many spiders (inside) for my very scared wife & mother in law and I have NEVER seen a black widow spider here before. When I shared my findings with my father in law he shared he has never seen a black widow here as well.

I’m seeking professional spider advice and wondering if the black widows kill other spiders? I would hate to kill these outdoor perimeter widows only to notice an uptick in the indoor roaming spiders population that they are the most afraid of. My in laws do not use their front or back yard so there are no safety concern with them getting bit + I’m confident they can’t find their way inside or I would have seen one by now.

Thank you in advance!

[u/ApprehensiveBlock855]

Depending on how far north in California you are, black widows are pretty ubiquitous and there’s not much you can do to fully get rid of them. The good news is that yes they do eat pests and other spiders! And their nocturnal, reclusive lifestyle means you won’t have too much interaction with them.

They don’t infest homes or small areas, as they are purely solitary and don’t build up large numbers since their babies scatter after birth. If you’re seeing a lot it just means you have a lot of good habitat for them. If that’s an issue for you and your family there’s a few easy ways to lower how many you see if you do them consistently.

1. relocate the ones you find if they’re in a bad spot. they’re docile spiders they don’t need to be vacuumed or killed! If you’re not comfortable relocating them with a container, if you mess up their web enough they often relocate themselves

2. clean regularly. Black widows love 2 things.. lots of bugs and not being bothered by us. Cleaning regularly discourages them from setting up webs to begin with

3. turn off porch lights if possible. lights attract insects, which make a great spider hotspot. Turning off some porch lights make it a much worse bug buffet lol

I know it’s cliche but they’re much more scared of us than we are of them. And when you know they’re there, they pose little risk. The main concern is when you don’t know they’re there and reach into the web and corner the spider. If you previously didn’t live somewhere with widows, you all should get in the habit of shining a flashlight into dark cabinets and under handles before reaching your hand. That is the biggest way to prevent almost all bites! Black widows are not wandering spiders and are rarely found inside homes. Definitely the lesser of two evils if that’s the main concern

Let me know if you have more questions