You need to find the nest. Buy a proprietry ant powder. Follow the instructions, which normally entails putting the powder around the entrance to the nest. The ants then pick up the powder, carry it into the nest and eventually it gets taken down to the queen, killing her. The nest cannot survive without the queen. Also there is 'Nippon' which is a sweet liquid poison that gets fed to the queen- same result. If you cannot find the nest, use either on one of the ant runs. Might take longer, and more than one application. Ants use regular runs, once a source of food is found. Remember, whatever you use is a poison, so do not use on surfaces where it might come into contact with food, and think about pets and kids. Your local council should be able to help, either with advice or they can come and do it for you, but will charge for the service.
After you solve the problem, you need to look at why they are coming in in the first place. Usually, scout ants look for food, and if they find it will go back to the nest and use chemical signals to tell worker ants where it is. Check you do not have any food waste finding its way into cracks or crevases. Remember, what seems like nothing to you is a veritable feast to an ant! Even a grain or two of spilt sugar will have them coming back for more.
Paul Higgins., July 2005
