Slugs in the home: causes and long-term fixes

Written by Avon Pest ControlFirst published 15 February 2026Updated 9 November 2026

One slug on the kitchen floor is bad luck. Slugs every few mornings mean the conditions in and around the house are inviting them in. The long-term fix is changing those conditions, not finding a stronger product.

The short version

• Slugs come indoors for moisture, shelter and easy access.
• Repeat visits usually point to damp, poor drainage or gaps around doors and pipework.
• Sealing entry points and reducing moisture stops them. Salt, pellets and barriers do not.

Why slugs come indoors

Outdoors, slugs spend the day under stones, plant pots, leaf litter and decking, and come out at night. Indoors they look for the same things: somewhere cool, damp and dark, close to where they got in. The usual reasons a house attracts them are:

• Damp floors or walls.
• Poor drainage, with water collecting against external walls.
• Gaps under doors or around pipework.
• Cracked brickwork or air bricks with no mesh.
• Plants, soil or decking right up against the house.
• Food left out in kitchens and utility rooms, including pet food.

Once inside they travel at night and spend the day behind appliances, under kitchen units and along skirting boards.

Are slugs harmful?

Slugs do not bite. They can carry bacteria on their bodies and in their slime, so surfaces they have crossed in food areas need cleaning, and they will eat pet food and houseplants. Slugs and snails can also carry lungworm, which can be serious for dogs that eat them.

The bigger issue is usually what their presence points to. Regular slug activity indoors often goes with damp or drainage trouble, and left alone that leads to mould, rot and other pests that like the same conditions, such as woodlice and mould mites.

Signs you may have a slug problem

• Silvery trails on floors, walls or worktops, often first thing in the morning.
• Damage to houseplants or vegetables stored indoors.
• Slugs in sinks, near external doors or around the washing machine.
• More activity after heavy rain.
• Damp patches near where they appear.

Why DIY fixes often don't last

Salt, barriers and pellets deal with the slug in front of you at best, and salt and pellets do not belong indoors at all. None of them changes why slugs keep arriving. What lasts is:

• Finding and closing the entry points.
• Reducing damp and excess moisture.
• Improving drainage and airflow.
• Removing shelter outside, such as leaves and dense planting against the walls.

Preventing slugs in your home

• Trace the route. Follow fresh trails back after dark or first thing in the morning. See how slugs find their way into UK homes.
• Seal gaps under doors and around pipes, and fit fine mesh over air bricks without blocking them.
• Sort the drainage. Keep gullies and drainage channels clear, fix leaking gutters and downpipes, and make sure ground or paving falls away from the house.
• Keep the damp-proof course clear. Soil, gravel or paving piled above it lets damp into the wall.
• Clear the wall line of leaves, pots, logs and dense planting.
• Ventilate and fix leaks in kitchens and bathrooms.
• Keep food areas clean and pick pet bowls up overnight.

For removing the slugs already inside, see how to manage indoor slugs safely.

Don't let slugs settle in

If slugs keep coming after you have worked through the list, we can trace the entry route and recommend proofing for those points. Where the real cause is damp, drainage or a leak, the right person is a builder, plumber or damp specialist, and we will tell you that rather than sell you something that will not work.

How slugs get in → Removing slugs safely →