How to get rid of ants in the house

Which ants come into UK homes?

Usually the black garden ant, Lasius niger. Despite the name, the BPCA says it is actually very dark brown. Workers are 3 to 5mm long.

They nest outdoors under paving stones, in soil and between brickwork. Kent Wildlife Trust says a colony has thousands of workers and a single queen who lays all the eggs.

	Black garden ant	Pharaoh’s ant
Colour	Very dark brown, looks black	Small, yellow or light brown
Size	Workers 3 to 5mm	Much smaller than a garden ant
Food	Sweet things	Protein rather than sugar
Nest	Outdoors: under paving, in soil and brickwork	Inside the building, in hard-to-reach places
Where you see it	Kitchens, looking for sweet food	Centrally heated flats, student halls and hospitals
Can you treat it yourself?	Yes, with care	No, call a professional

Where are they getting in?

Find the trail before you do anything else. The ants you see are foragers carrying food back to feed the larvae and the queen.

1. Watch the line. Follow it back from the food to the point where it disappears, often a gap by a door, window, pipe or skirting board.
2. Look outside the same wall. The BPCA says nest entrances show as small piles of earth pellets, often between paving slabs or along the house wall.
3. Note the spot. That’s where bait goes, and later where you seal the gap.

How do you stop attracting them?

• Keep sugar, honey, jam and syrups in sealed jars or tubs.
• Wipe up sticky spills and sweep crumbs, including under the toaster and kettle.
• Rinse drinks cans and jars before they go in the recycling.
• Don’t leave pet food down longer than needed.
• Once the ants have gone, fill small gaps around pipes and door frames.

Why doesn’t spraying the trail work?

Spraying kills the workers you can see. The queen stays safe in the nest, laying more eggs.

The BPCA goes further: insecticidal sprays and dusts are generally ineffective and make ants scatter and colonies split. You can end up with more nests, not fewer.

Bait works the other way round. The BPCA says sugar-based liquid baits attract workers, which carry the bait back to the queen and larvae and destroy the colony from inside. Leave the trail alone while they feed, and follow the label exactly.

The BPCA says shop ant products are only suitable for black garden ants, and only if used as the label directs.

What about nests outside?

Outdoors, the BPCA says black garden ants can usually be left alone. They only become a problem when they come inside.

Homes in Farnham Common and Burnham with patios, or gardens backing onto fields, are likely to have ants nearby. Focus on keeping them out of the kitchen rather than clearing the garden.

Pouring boiling water over a nest is, in the BPCA’s words, first aid rather than a fix. Winged ants in summer are a separate event: see flying ant day: when it is and what to do.

When to call someone

Call if bait hasn’t cleared them, if they keep coming back, or if you’re seeing very large numbers.

Call straight away if you see tiny yellow or light brown ants in a centrally heated building. The BPCA says Pharaoh’s ants nest in hard-to-reach places and split their colony to spread, so they should only be dealt with by professionals.

Our ant treatment starts from £99 including VAT for one treatment. We call back within 30 minutes during opening hours, Monday to Saturday 8am to 6pm. We agree a fixed price on the phone before anyone visits. Visits are usually [same or next day].