Hi last night I found a huge spider running alongside the skirting boards on the floor under the radiator. I have never seen a spider that size in the uk before that was not in a pet shop. my husband saw a very large spider last year but failed to catch it. He pulled the whole house apart checking every wall to see where it could of gotten in. He's a builder so did check thoroughly. He kept saying how huge it was which makes me think maybe this was the same spider.

I now can't sleep in case it's laid any eggs! we did get a barely new divan bed from a relative. Do you think it could of come/been living in the bed?Both times the huge spiders were lurking in our bedroom! I did manage to catch the spider by candle light and it was pretty fast but seemed to stop for rests. The upside down cup was barely big enough to catch it!! I flushed it away as was terrified. What can I do to prevent these? And how has it got in? My house is very clean!!

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Hi Beth.

Well, ok, I'll try and cover some key points. It would have been helpful to know if in UK or not, as if not i'd have to adapt some things. I'm expect you're UK though. Firstly, I should say that personally I like spiders very much. There are only a very few kinds which need caution (i.e. where some problem can happen for people if bitten), but VERY FEW kinds. And the ones i mean are not native to the UK. Having learnt about them, i'm pretty clear which to be wary of, and this certainly isn't one of them. Infact, to go on a tangent for a moment, i'd suggest that the vast majority of what anyone might read in UK newspapers about spiders is over-hyped, or utterly misleading. So if you've got any thoughts from what you've read in newspapers in mind, please put all that aside for a few moments.

What i'm pretty sure you've got there is probably one of the common UK 'house spiders'. The scientific name Eratigena atrica is probably the best to take a look at for information, although you might come across several other competing names for the same 'giant' species in the UK. Another closely related yet common suspect is the slightly smaller Tegenaria domestica.

Here's the good news. No eggs for sure. Even though the photo is distant, i can see the front two leg-like structures (called pedipalps) had swollen tips. That means it was a mature male - and hence - no chance for eggs anywhere from it! Currently being autumn, it's now the peak mating season for these types, the males simply go off wandering in search of females. He was actually trying to find the other spiders also. If you didn't find them, chances are good that he didn't either. When young (immature) the males live in rather tangled/messy webs, as females do. Both sexes moult their exoskeleton a few times as growing. But then the males go through a final transformational moult, then start roaming.

Ok, as probably a 'Giant house spider' I'd agree they can be impressively large (deserving the name giant!), and there have been other reports of exceptional ones this year - the spring and summer were ideal this year with lots of food around to help them grow quickly to their big proportions. Also i'd agree they can seem scary - they don't move slowly, but rather indeed make frantic dashes. Good news though is that when stopping, they stop because they've effectively run out of steam - they don't get oxygen to muscles as efficiently as we humans do, and hence the spider's muscles quickly get exhausted.

So to the questions - I'm expecting it is a different one from last year. The roaming mature males like this will typically have just one mating season then die in winter. So i expect it was a different hopeful male this time last year.

Here's the bad news. I expect it was in your house all year, maybe several years. You only saw it when it emerged to go searching for a female. Even the cleanest houses have lots of spiders, and they're nothing to be worried about in the UK. Infact, i'd argue they're beneficial, limiting any other intruding 'bugs', even other smaller types of spiders. The good question now is what was it eating before roaming? Honestly though, it could have simply wandered in from outside, if you'd left a door open for summer etc. Even might have come in under a natural crack under a door etc. Sorry, but you'll never prevent them coming in, and even the cleanest house will have several spiders. I hope you find peace and acceptance with them. I'm also sorry to see it ended up flushed. I ask kindly that in future you simply take a few more moments after catching to simply go release it outdoors, they certainly don't have anything like a homing instinct, it will simply wander off in a random direction .... please consider it, they're harmless (and to me at least, they're wonderful animals)

Last edited by Stuart Longhorn (23rd Aug 2015 23:17:50)