Large House Spiders in Autumn: Why You See More

It is a familiar scene: you come downstairs, and there is a spider the size of a hand in the bath or sprinting across the carpet. It feels like an invasion, but it is a seasonal habit.

Here is why large house spiders seem to multiply in autumn and what you can sensibly do about it.

What is really happening

Most of the big spiders seen indoors in autumn are adult males of the house spider group. They have spent the summer growing, and now they leave their webs to look for a mate.

That wandering takes them across floors, up walls and along skirting boards, which is why you notice them more. There are not more spiders; they are just on the move.

Their legs can look enormous when they run across a pale carpet, which adds to the shock. Size is mostly a matter of perspective, since they are quite light and fragile.

Why they come indoors

Cooler nights make warm buildings attractive, and a house offers shelter, a steady supply of small insects and plenty of quiet corners.

They also get in simply by wandering. Gaps around doors, vents, pipes and window frames are all easy routes for something that can flatten its body to squeeze through.

A house with lots of ground-level gaps, a conservatory, or a garage joined to the main building often sees more visitors than one with tightly fitted doors.

The bath mystery

Many people find a large spider in the bath or sink in the morning. The usual explanation is that it climbed in, perhaps drawn by moisture, and then could not scale the smooth, slippery sides to get out.

If you want to help it out, lay a towel over the side as a ramp, or use a cup and a piece of card to move it outside.

• Keep a cup and card handy for relocating
• Check shoes and towels left on the floor
• Look behind furniture when cleaning
• Do not assume a spider is dangerous because it is large

Should you be worried?

Large house spiders are not dangerous to people. They are fast and look alarming, but they are shy, and will run from you rather than towards you. Their bite is very unlikely and not of medical significance.

They also eat flies, moths and other small insects, so a few can be useful. If you have a persistent fear of spiders, that is understandable and worth acting on, as there are practical steps below.

Cutting down on encounters

Vacuum corners, under beds and behind furniture, and remove webs and egg sacs as you find them. Reduce clutter, especially boxes stored on the floor, which give spiders places to hide.

Sealing gaps around doors, pipes and windows helps, and so does cutting back plants against the walls. If spiders are a regular problem, Essex Pest Solutions offers spider control for homes and businesses across Essex, based on what an inspection finds.

Try not to treat every sighting as an emergency. A single spider in a room is normal, while many spiders and webs in the same spot suggest something is feeding them nearby.

Frequently asked questions