You come down in the morning and there's a silver trail looping across the kitchen floor. Once the autumn rain sets in, working out how to get rid of slugs in the house becomes a nightly job: they come in after dark, eat whatever they find and are gone again before you're up. Dealing with the one you can see achieves nothing, because the slug isn't the problem. The gap it came through is.
Why slugs come indoors in autumn
Slugs need constant moisture and they feed when it's cool and wet — which, from September on, means most nights. If there are pots, fallen leaves or a stack of firewood beside your back door, there's a colony living a metre from the threshold. From there they squeeze through any gap, head for whatever smells of food (the cat's bowl, a damp cloth, the bin) and crawl back to their hiding place before dawn, following their own slime trail like a marked path.
That last bit explains the maddening part: they come back the same way, night after night.
Step one: find where they're getting in
This is the step almost everyone skips, and the only one that actually fixes it. Go out with a torch around eleven at night with the lights off. The fresh trail glistens, and you can follow it backwards to the exact entry point. It's usually one of these:
- The gap under the back door or patio door.
- Airbricks and low-level vents.
- The hole around a pipe under the sink, behind the washing machine or at the boiler.
- An open joint between the skirting board and the floor.
- The cat flap, and the bottom of the garage door.
Step two: seal it
Once you've found the point, close it. A brush strip or draught excluder along the bottom of an external door solves most cases on its own, and it keeps the heat in too. Cover airbricks with fine wire mesh — don't block them completely, they're there to stop damp. Fill pipe entries with sealant or expanding foam, and check for perished silicone under the kitchen units.
Step three: wash the trail away
Dry-sweeping does nothing, because it leaves the chemical signal they navigate by. Scrub the whole run with hot water and a degreasing detergent, or a diluted white vinegar solution, then dry it. With the trail gone, the route stops existing as far as they're concerned.
Make the kitchen boring after dark
Before bed: lift the pet bowls off the floor, wring the cloth out and don't leave it in the sink, tie the bin bag, dry the floor if you've just mopped, and put fruit away. A dry kitchen with nothing to smell isn't worth the trip. You'll find kitchen and storage bits in our shop.
Then sort out the doorstep
Move pots, pot saucers and low ground-cover planting away from the door, clear wet leaves and shift the log pile. If the coir mat stays soaked all week, it's a perfect hiding place — swap it or stand it up to dry. While you're there, look at any gutter or downpipe dripping beside the door.
What not to bother with
- Salt on an indoor floor. It stains, it damages the finish, and it doesn't stop the next one coming in somewhere else.
- Slug pellets inside the house if you have a dog, a cat or small children. That's a garden product, used carefully.
- Beer traps indoors. They pull in more than they catch. Outside only, and well away from the door.
- Removing the slug and leaving it there. If the trail stays and the gap stays, there'll be another one tomorrow.
In short: find the entry point at night with a torch, seal it, scrub the trail off with detergent, and keep the kitchen dry and cleared. Do those four things and it stops, instead of repeating every morning until spring.