The nest is outside and normal. The trail into your kitchen is the actual problem, and it is usually crossing a junction you can find in five minutes.
Because there is a nest outside — which is entirely normal — and something inside worth walking to. The route between the two is almost always a gap where the ground meets the building.
The nest is not the problem and does not need destroying. The route is the problem, and closing it is usually a small job.
A garden ant colony sends out scouts constantly. Most find nothing. One finds a crumb behind your patio door, lays a trail on the way home, and by the next morning there is a line of them crossing your kitchen floor.
The reason it happens at the back of a house so often is structural. The junction where a patio, path or decking meets the house wall is a warm, sheltered, undisturbed strip of ground — excellent nesting habitat — and it sits directly against the building with a route in at the top of it.
Work from the inside out. Do not clean the trail until you have followed it.
This is where people spend money unnecessarily. A nest under a patio slab is a normal feature of a garden. Garden ants aerate soil, predate other insects, and cause no structural harm to paving or buildings in this country.
You do not need to eliminate it. You need to stop it having a reason and a route into your kitchen.
There is a nest under nearly every patio in the country. The ones that become a problem are the ones with an open door.
See our complete service, published prices and treatment information.
View Ant Control Harrow Weald →Once you know where they cross, this is often a genuinely small job:
| Entry point | What usually fixes it |
|---|---|
| Patio or path meeting the wall | Sealant or mortar along the junction |
| Gap under a back or patio door | Threshold seal or brush strip |
| Crack in mortar at ground level | Repointing, or sealant as a stopgap |
| Around a waste or service pipe | Silicone sealant |
| Air brick | Fine mesh cover — do not block it, it is there for ventilation |
| Window frame at ground level | Re-seal the perimeter |
One note on air bricks: they exist to ventilate underfloor voids and blocking them entirely causes damp problems. Cover with mesh rather than filling.
Alongside the route, remove what is drawing them. Ants come in for sweet and greasy food, so:
If you have closed the route, removed the food and cleaned the trail properly and they are still coming in a fortnight later, treatment is warranted. That usually means either a route you have not found or a colony large and established enough to keep probing.
We treat the colony producing the indoor activity rather than the garden generally. If the honest answer is that you have an ordinary garden nest and a gap you have not yet sealed, we will tell you that.
Read nextHow Do You Get Rid of Ants Coming Into a Harrow Weald Home? →For a few days in warm weather, usually mid-summer, colonies release winged reproductives all at once. It is startling, it happens across the whole area on the same day or two, and it is over quickly.
It is not a reason to treat, and it does not mean a new problem. The winged ants disperse or die within days.
Plenty of Harrow Weald HA3 properties have a patio, path or extension meeting the house at the rear, and that junction is the single most common ant route indoors here. If yours has opened up over the years, that is usually where to look first.
They can bring fine soil up between slabs and, over years, contribute to a slab settling slightly. It is a maintenance issue rather than damage, and not a reason for pest control.
We would not. It is disruptive, it rarely gets the whole colony, and a garden without ants is not an improvement on one with them.
Heavy rain floods shallow nests and pushes activity toward drier ground, which frequently means the sheltered strip against your house and then inside it. It usually settles once the ground dries.
Something else appearing in the garden? Wasp nest treatment in Harrow Weald is a £90 fixed cost with our guaranteed service.
There is a nest outside, which is normal, and something inside worth walking to. The route between is usually a gap where the ground meets the building.
No. Garden ants are normal and cause no structural harm. Closing the route indoors is what matters.
The junction where a patio or path meets the house wall, and gaps under back or patio doors.
Cover it with fine mesh rather than filling it — air bricks ventilate underfloor voids and blocking them causes damp problems.
Heavy rain floods shallow nests and pushes activity toward drier sheltered ground, which is often against the house.
No. They are the reproductive stage, they appear for a few days in warm weather, and they resolve on their own.
If they are still coming in a fortnight after you have sealed the route, removed the food and cleaned the trail properly.
Tell us where they cross into the building. If it sounds like a gap you can seal yourself, we will say so.
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