Start by Understanding What You Are Up Against
The ants crossing your floor are not the problem. They are sterile workers sent out to find food, and behind them is a nest with a queen who is laying more every day. For the common black garden ant that nest is nearly always outside, under a slab, a patio or the base of a wall, and the queen never comes indoors.
So anything that only deals with the ants you can see is tidying up. It can make the kitchen pleasant again for a day, but the nest simply sends more. Everything below is aimed either at stopping the house being worth visiting, or at getting something back to the queen.
Step One: Break the Trail
A forager that finds food lays a scent line on the way home, and the others follow it. That line is why one ant on Monday becomes a procession on Wednesday, and it stays on the surface after the ants have gone.
Wipe the whole route with warm water and ordinary washing-up liquid, not just the patch where the ants gathered. Follow it along the skirting, across the threshold and up the cupboard side if that is where it runs. A kitchen spray that smells strongly of lemon can mask the scent for a while, but detergent actually lifts it.
Step Two: Take Away the Reason to Come In
- Sugar, jam, honey and syrup into screw-top jars or sealed tubs. A clipped bag is not sealed as far as an ant is concerned.
- Crumbs and spills cleared each evening, including under the toaster and along the back of the worktop.
- Pet food picked up once the animal has eaten, rather than left down all day.
- Recycling rinsed, especially juice cartons, cans and anything that held fruit.
- Bins with lids that shut, and the kitchen bin emptied more often while the ants are about.
None of this touches the nest, but it takes away what the foragers are reporting back about, and a house with nothing on offer soon stops being worth the trip.
Step Three: Use Gel Bait Properly
A shop-bought ant gel or bait station is the one home product that can reach the queen, because the workers carry it back and share it. It works only if they are allowed to do that.
- Put small spots of gel on the trail itself, near where the ants are coming in, and out of reach of children and pets.
- Leave the ants alone. Seeing them crowd onto the bait is the point, not a sign it has failed.
- Do not spray, wipe or pour anything on the trail near the bait. That kills the carriers and teaches the rest to avoid the spot.
- Top it up if it dries out or disappears, and follow the directions on the pack.
- Give it a week or so before judging the result.
The single biggest mistake is killing the ants that are eating the bait. Every one of them is a delivery on its way to the nest. Put the spray away while the gel is out.
The quick fixes most people reach for first, such as aerosol sprays, powders and a kettle of boiling water, kill the ants they touch and leave the nest alone; the page on why those disappoint goes through each one.
Step Four: Seal Up, but Only Afterwards
Filling the gap at a threshold, a patio door frame or along the skirting is worth doing once the activity has stopped. Doing it while a nest is still active mostly redirects the ants to the next gap along, and occasionally traps a nest inside a wall base where it is harder to reach.
When It Is Time to Call Someone
Ring if the trail is still there after a fortnight of the steps above, if ants are coming up from under the floor or out of a wall rather than in from the garden, if there are flying ants indoors, or if the ants are tiny and pale, which can mean pharaoh ants. Professional ant control is a fixed £240, confirmed before anything is booked, and how the treatment works is explained separately.