How Do You Know If You Have Ants in Greenwich?

The One Thing to Look At

Not the ants. The line.

A few ants wandering across a floor in July are foragers and mean very little. What matters is whether they are following a consistent route - the same line, along the same edge, day after day, with traffic going both ways.

That line is the single most informative thing in the property, because ants lay a chemical trail between a food source and the nest and then follow it faithfully. Which means the trail is a map, and following it to where it leaves the building tells you more in two minutes than any amount of looking at the ants themselves.

Following It Out

1. Find where the line enters the room. Under a kickboard, along a skirting, at a pipe entry, around a door frame, up from a gap at the floor.
2. Go outside and look at the same spot from the other side. A doorstep, a path edge, a patio joint, the base of a wall.
3. Look for fine excavated soil. Small piles of loose crumbly material between paving slabs, at a path edge or on a step. That is the nest telling you exactly where it is.
4. Follow it further if it keeps going. Over a boundary, under a shed, into a bank of soil, towards a neighbouring garden.

Where the line stops is the answer, and it changes what should happen next.

Is It Even a Problem?

Worth asking honestly, because a proportion of ant enquiries do not need a treatment.

Flying Ants Are Not an Infestation

For a short spell each summer, mature nests release winged males and new queens at roughly the same time across a wide area. It is dramatic, it lasts days, and it is not a reason to treat the house they emerged beside.

What it does tell you is that there is a mature nest close by - useful if you have had a trail indoors and could not work out where from. Treating the swarm itself would be selling you something that solves nothing, and we will say so on the phone.

Which Ant?

Usually it does not matter much, and occasionally it matters a great deal.

The black garden ant is what almost every domestic enquiry turns out to be. Dark, familiar, nesting outdoors in soil and under paving, coming indoors to forage. Straightforward to deal with.

The pharaoh ant is different and worth ruling out in a heated block. Much smaller, yellowish to light brown, and it nests inside warm buildings rather than in the garden - in wall voids, around heating pipework and service runs. It is the one species where getting the treatment wrong makes things markedly worse, because chemical disturbance can cause the colony to split and relocate into several new nests.

If the ants are very small, pale, indoors all year rather than seasonally, and in a heated block or a converted building, say so at the enquiry. A photograph helps.

The Mistake That Makes It Worse

Reaching for a household spray. It kills the workers it lands on, which the colony replaces continuously, so the trail is back within days - and heavy chemical disturbance around a nest can cause it to fragment into several smaller nests in new places.

One trail becomes three, in three parts of the building. If you have already sprayed, tell us - it does not change what we will do, but it changes where we look.

What to Send With Your Enquiry

• Where the trail runs and, crucially, where it disappears to.
• Whether you found excavated soil outside, and where.
• Whether it is a house, a ground-floor flat or an upper-floor flat.
• Whether anything has been sprayed already.
• A photograph if the ants look small and pale rather than the familiar dark garden ant.

If It Started After Building or Garden Work

A surprisingly common trigger, and worth mentioning at the enquiry because it explains a trail that appeared out of nowhere.

• New paving, a patio or a path. Fresh sand-bedded slabs over well-drained ground are close to ideal nesting conditions, and a colony can establish in a season.
• A driveway or hard standing laid recently. Same reason.
• Ground levels raised against a wall. Made-up ground next to a building puts a nest within centimetres of the inside.
• An extension or a rear return. New junctions between old and new brickwork frequently leave routes at ground level that nobody notices.
• A garden cleared or re-landscaped. Disturbance moves colonies, and one that was fine at the bottom of the garden may relocate against the house.

None of it is anybody's fault and none of it means the work was done badly. It simply means the conditions changed, and knowing when the trail started relative to the work usually points straight at where the nest is.