Pest Control
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On a warm, humid afternoon in high summer, winged ants can pour out of cracks in the patio, gather on walls and drift through open windows in their hundreds. It looks like an infestation. In most cases it is a few hours of mating flights and is over by evening.
What flying ants are
An ant colony is made up mostly of wingless female workers. Once a colony is large and well established, it raises a batch of winged males and winged young queens, known as alates. These stay in the nest until the weather is right, then leave together to mate in the air.
After mating, the males die within a day or so. Each mated queen lands, breaks off her wings and looks for somewhere to start a new colony, usually a crack in the soil or under a stone. Very few succeed.
Why they all appear at once
In the UK most flying ants are black garden ants, and their flights usually happen in July and August. Colonies across a wide area tend to release their alates on the same warm, humid, still afternoons, often after rain, which is why the papers talk about "flying ant day". In practice it is usually a series of days spread across several weeks, with different areas swarming at different times.
Swarming together gives queens from different colonies the best chance of finding a mate, and the sheer numbers mean some survive the birds and other predators that feast on them.
Flying ant or wasp?
People sometimes mistake flying ants for small wasps. A flying ant has:
- A pinched waist, with a small bump or node between the thorax and abdomen.
- Elbowed antennae, bent like an arm.
- Two pairs of wings, the front pair noticeably longer than the back pair. The wings snap off easily, so you will often find loose wings on sills and paving.
- A dark brown or black body, without the bright yellow and black of a wasp.
Black garden ant queens are much bigger than the workers, up to about 15mm, and males are smaller and slimmer. Flying ants do not sting.
Are flying ants a problem?
Outdoors, no. A swarm tells you there is a mature colony nearby, which in most gardens is no surprise. The flights are over within hours and the ants do no harm.
Indoors, it depends where they are coming from. Flying ants that drift in through an open window are passing through and can be vacuumed up. Flying ants that appear from skirting boards, floorboards, around a fireplace or out of a wall mean the nest is in, or under, the building. That is worth dealing with, because the same colony will be sending workers into the house for food.
What to do during a swarm
- Close windows and doors on the side of the house where the ants are gathering.
- Vacuum up any that get indoors and empty the vacuum outside.
- Do not spray the swarm. It will be over by itself, and spraying flying ants does nothing to the colony they came from.
- Note where they came from. A gap between paving slabs or the base of a wall tells you where the nest is, which is useful if the same colony sends workers into your kitchen.
Preventing problems later
The colony is the thing to manage, not the swarm. Seal cracks around door and window frames and where pipes enter the house, keep food sealed and surfaces clean, and keep plants and garden debris away from the walls. If the same nest causes trouble indoors through the summer, the advice in our guide to black ants in the house applies.
When to call us
Call us if flying ants are emerging from inside the house, if they appear indoors year after year, or if the colony they came from keeps sending ants into your kitchen. We find the nest and treat it at source. See our ant control page for how we work.