Black Ants
Black ants (Also known as 'lasius niger') are commonly found throughout the UK, and although they nest outdoors, they are often found inside houses causing a nuisance more than anything.
They are social creatures, and live in colonies containing workers (infertile females), males, queens and grubs (larvae). Ants mate on the wing, so the "flying ants" are either males or immature queens.
Where do they come from?
You will find ants nests in dry earth around plant roots, with sandy soil in particular attracting colonies.
The sand used in house foundations, garden paths and patios forms a good site for the queen ant to start a colony. Nests are increasingly being found inside the walls of properties (cavity walls, for example). Once a colony develops it can be difficult to get rid of.
Why do ants come indoors?
The ants found indoors are usually worker ants, which are foraging for food for the queen and grubs. They have found that buildings inhabited by humans are a good source of provision, particularly sweet or sugary items.
Do black ants just live on human food?
No, the worker ants are scavengers and collect seeds, nectar, even dead insects to take back to the nest. They also prey on greenfly, blackfly and other small insects, so cannot be considered to be all bad
Do black ants do any harm?
Although it is unpleasant and a nuisance to find a large number of them in your home, black ants do not transmit any serious diseases.
However ants may have travelled through unpleasant or dirty places during their foraging and before entering your home. This means that they can taint any food, making it unsuitable to eat.
Do not leave food uncovered if accessible to ants. If they have contaminated food dispose of it in the dustbin (wrapped first to prevent it smelling in the warmer weather).
How do I get rid of them?
The cheapest, but not necessarily most successful, way of dealing with an ants' nest is to pour boiling water onto the nest. This will certainly control the problem, but may only be a temporary solution.
Another way is to buy a household insecticide which you should apply on and around the nest, together with possible entry points for the ants. Entry points would include doors, windows, cracks in walls, even waste pipes. Remember, for your own safety, to follow the manufacturers' instructions on the pack.
This again may only be a short term answer, firstly because of the low dosages allowed in domestic insecticides. Secondly, there can be so many ants in one nest that it is difficult to eradicate the whole colony in one go, so the problem may recur.
A more permenant solution, but one that takes a long time, is to buy a hormone preparation. This comes in a sugar solution, which you place on ceramic or glass containers. The ants take this back to the nest and feed it to the queen. It makes her unable to lay fertile eggs and the nest gradually dies off. It takes at least six week before you notice the treatment working.
Last updated Thursday the 13th of December 2007.
