Ants
Dry Ground and Damp Ground in One Garden
Near the brook, lower lawns and borders stay moist for much of the year and can be soggy after heavy rain. Black garden ants prefer loose, warm, free-draining ground, so in a garden like this they move uphill, towards the patio, the path along the back of the house and the foot of a sunny wall. That is also where the kitchen is. The brook corridor itself is covered on Pest Control Whetstone.
Under the patio by the back door
The sand bedding under paving slabs warms quickly in the sun and drains well, and a colony can live in it for years. Fine soil pushed up between slabs, or ants vanishing into one joint, marks the spot. Where ants nest around houses covers the other spots worth checking in a sloping garden.
Steps, raised beds and retaining walls
Sloping gardens are often terraced, with steps, low walls and raised beds holding the soil back. The dry, stony backfill behind a retaining wall is another good nest site, and ants can reach the house by running along the top of the wall or the edge of the steps.
Mounds on the lower lawn
Small domed mounds in the grass further down are usually yellow meadow ants. They spend nearly all their lives underground and seldom come into houses, so a mound-covered lawn near the brook is a gardening question rather than a sign the house is affected.
Following the Trail Indoors
Watch where the ants go on a warm day. Trails usually run along the skirting on the garden side, from a back door threshold, a patio door frame or the hole where a waste pipe leaves the kitchen. Tracing the line outside to where it disappears shows roughly where the colony is, and how to find an ant nest shows how. On a few humid days in summer, winged ants may stream out of the same joint; why flying ants suddenly appear explains that it is short-lived. Insects using one hole all day for weeks are a wasp nest, not ants.
Ants in High Road Flats
In a flat above the shops or in a block along the High Road, ants are less likely to come from a garden. Very small, pale yellowish ants in a warm building could be Pharaoh ants, which are rare in houses but can spread between flats along heating and pipe runs. Spraying them can make the colony split, so read Pharaoh ants vs garden ants and tell us their size when you book. Small insects that run for cover when the kitchen light goes on at night may be cockroaches.
Before and After the Visit
- Tell us whether it is a house or a flat, and where the ants are coming in
- Say whether the garden slopes towards the brook and where the patio and paths are
- Stop spraying and wipe worktops with warm soapy water, so the trail is still there to see
- Keep sugary food sealed and lift pet bowls at night
Ants may still be about for a while after the visit, depending on the size and position of the colony, as how long ant treatment takes explains. If activity has not dropped off, get back in touch.
Keeping Ants Out of the Kitchen
- Re-point cracks along the back door threshold and round patio door frames
- Brush kiln-dried sand into the patio joints each spring
- Leave a gap between raised beds or pots and the house wall
- Keep aphids down on shrubs near the back door, since ants tend them for honeydew
- Sweep fallen fruit and bird seed off the patio
The borough-wide page, Ant Control Barnet, covers ant nests in gardens and blocks elsewhere in Barnet.
