How do I keep spiders out of my house?

If spiders frighten you, dreading autumn in a house full of webs is a horrible feeling, and a very common one. No home is ever completely spider-free, but you can make yours a much less inviting place. Spiders go where their food is, and their food is other insects. So the plan is simple: fewer insects, fewer ways in, and regular clearing of webs and egg sacs.

Why they come in

Spiders come in through gaps, follow insects drawn to lights and damp, and settle where it is quiet: corners, behind furniture, in boxes on the floor. Many house spiders live indoors all year, out of sight. In many places you see more of them in late summer and autumn because adult males start wandering to find mates, not because they have all just arrived from outside.

The plan

1. Close the gaps. Around window frames, where pipes and cables come through walls, along skirting boards and under kitchen units. A hole in a ceiling opens onto a void full of insects, so fill it or cover it. See sealing gaps and blocking entry.
2. Cover vents without blocking them. Fit fine insect mesh over air bricks and vents. An extractor fan with a flap that closes when it is off keeps more out. Never seal a vent shut, because rooms need the airflow.
3. Fit door sweeps and fly screens. A brush strip under outside doors, and screens on windows you open in the evening.
4. Turn the lights down. Switch outdoor lights off when you do not need them, close curtains at night, and move a porch light away from the door if you can. Lights draw insects, and insects draw spiders.
5. Vacuum webs and egg sacs every week or two. Corners, window frames, behind furniture, under beds. Egg sacs are small round balls of silk. Empty the vacuum outside.
6. Clear the edges outside. Cut plants back from walls and windows, move log piles, pots and clutter away from the house, and sweep courtyard corners.
7. Tidy the floor indoors. Boxes and bags on the floor are perfect hiding spots. Store things in sealed plastic boxes, and use a dehumidifier in damp rooms, since damp brings the insects spiders eat.

In a ground-floor flat with a garden, the doors, air bricks and gaps at floor level matter most. If you keep finding young spiders in one room, look for the gap nearest to where they appear.

What does not keep them out

• Conkers on the windowsill. A much-loved tip, but not an established way to keep spiders out. Your time is better spent on gaps and lights.
• Ultrasonic plug-in repellers. They do not do the job. More in do ultrasonic pest repellers work.
• Peppermint oil sprays. A strong smell, but not a barrier. Spiders still come in through the gaps.
• Spraying insecticide around the house. It may kill some spiders it lands on, but it does not close the gaps or remove the insects that draw them in.

The one that keeps coming back

Large spiders like the huntsman, common in Australia, often come in from the garden through doors, windows and gaps around frames, and sometimes ride in on cars or washing. Check screens for tears, fit door seals, and bring washing in before dusk. To move one out, cover it with a container, slide a card underneath and carry it outside, or open the nearest door and give it a gentle route out with a broom. See catching a big spider when you are scared of them.

Not sure what it is? Some regions have spiders with a bite that needs a doctor. If you do not know the spider, do not handle it, keep children and pets away, and see is this spider dangerous. If someone is bitten and it gets worse, see a doctor.

If the fear is running your life

A strong fear of spiders is common, and it is treatable. If it stops you sleeping, using rooms or enjoying your home, talk to your doctor. Talking therapies are an established treatment for phobias. In the meantime, keep a long-handled catcher or a glass and card by the door, and agree with someone in the house that catching is their job for now.

The spider guide shows the ones most often found indoors.