Why Hard Landscaping Suits Ants
A paved patio or drive is, to a black garden ant, close to ideal. The slabs and blocks sit on a bed of sharp sand, which is dry, loose and easy to dig. The paving above soaks up the sun and keeps the brood beneath it warm. And the joints between the units give the colony dozens of small, sheltered doorways.
On a modern plot there is often very little soil at all near the house. The lawn, if there is one, is a strip at the end; everything close to the building is paving, gravel or a path running straight along the wall. So the nest the ants in your kitchen belong to is very likely under something hard, a short walk from your back door.
Reading the Sand
The clearest sign is also the easiest to miss. Workers dig out bedding sand and pile it on the surface, leaving small, fine-grained heaps in the joints between slabs or blocks. They reappear the day after you sweep them away. Where the heaps cluster, the nest is below.
- Between patio slabs near the back door or under a garden bench, where the paving stays warm.
- Along the join where the paving meets the house wall, often at a downpipe or the corner of the building.
- In block paving on a drive, especially at the edges where the kerb blocks meet the path.
- Around the doorstep, where ants use the gap under the threshold as the easiest way into the house.
Watch on a warm afternoon, when foraging is busiest, and you can usually see workers going in and out of one or two of those joints. The step-by-step method of following a trail back is on our page about tracing the trail on your own property.
The Wall Base and the Way In
A nest right against the house is the one that sends ants indoors. Workers come up out of the joint at the foot of the wall, find the gap behind a door frame or where a pipe goes through the brickwork, and are in the kitchen in a few steps. Where a patio door or its slab is the route in, our page on patio doors and expansion gaps goes into that detail.
The thing to get right: treat the nest, then fill the gap. Sealing the joint or the threshold first only sends the ants to the next opening along the wall.
Does It Damage the Paving?
Slowly, a little. Ants moving sand out from under slabs can leave a patio uneven over the years and open up the joints so weeds get in. They do not eat the stone, the mortar or the house. What that does and does not amount to is set out in do ants cause damage to your home.
What Treatment Looks Like
The nest is treated where it is: a residual insecticide applied into the active joints and along the base of the wall, and gel bait placed in cracks indoors where workers are coming in, out of reach, so they carry it back underground. Nothing needs lifting. Ant control in Thatcham costs a fixed £240; we confirm that and explain what the treatment involves before you book.
Please do not sweep, jet-wash or re-sand the treated joints for the period we give you, and keep children and pets off those areas until they are dry. Mention young children, animals, fish tanks or anyone vulnerable when you call.