Spider Season: Why Spiders Fill Welsh Homes Every Autumn

Same fortnight every year. The evenings pull in, the heating clicks on for the first time, and suddenly there's a large, fast, self-confident spider crossing the living room floor at speed while everyone lifts their feet. Autumn is spider season in every Welsh home, and before you call anyone, including us, it's worth knowing what's actually happening.

They're not moving in. They mostly already lived here

The autumn surge isn't an invasion from the garden so much as a coming-out. It's mating season for house spiders, and the big, leggy ones sprinting across your carpet at nine in the evening are almost all males, out patrolling for females instead of sitting quietly behind the bookcase like they have all year. That's why you suddenly see them, and why they seem so purposeful. The population in your house hasn't exploded; it's just stopped being discreet. If that's not the comfort you were hoping for, the practical upside is real: this is a season, it runs a few weeks, and the traffic across your carpet drops away on its own as the weather cools.

An admission you won't hear from every pest controller

Most of the time, spiders in a house don't need professional treatment, and we'll tell you that on the phone rather than sell you a visit. They're not after your food, they don't damage the fabric of the building, and they quietly eat the insects you'd otherwise be ringing us about. For the common house spiders, the honest options are the glass-and-postcard, tolerance, or reducing what attracts their prey: fewer flies means fewer spiders, which is why the porch light and the unscreened kitchen window matter more than any spray.

The exceptions worth taking seriously

Two situations change the advice. The first is false widows, which are established in South Wales and worth treating with respect: a distinctive rounded, shiny abdomen with pale markings, found in sheds, garages, window frames and conservatories. They're not aggressive and bites are uncommon, but they can be unpleasant, so if you're finding them repeatedly where your children play or where your staff work, that's a reasonable call for you to make and we'll deal with it properly. The second is volume: webbing and spiders accumulating in numbers in a garage, outbuilding or commercial unit, which usually signals a thriving insect population feeding them, and the right fix is treating the cause as much as the spiders.

If you'd rather see fewer of them

Proofing works on spiders the same way it works on everything else: brush strips on external doors, sealed gaps around pipes and window frames, vents screened, clutter reduced along walls and in the corners they favour. Keep your outside lights off when you can or switch to less insect-attracting bulbs, and knock down webs regularly so your premises stop being good hunting. Our spiders page covers identification in more detail, and how we work generally is on our pest control page.

Get in touch

Finding false widows, or more spiders than a postcard can handle? Get in touch and we'll sort it, and we'll tell you honestly if you don't need us.