Controlling ants

Black ants, or garden ants as they are more commonly known, can become a problem during spring and summer months when they nest in and around buildings and gardens.

Large swarms of flying ants can sometimes emerge from early spring. These are mating ants. Swarms may last up to three hours. After mating, the males die but the females shed their wings and dig a cell in the soil where they may start new nests.

Ants feed on a wide range of foods but are particularly attracted to sweet substances such as sugar or honey, and often invade homes, kitchens and cupboards in search of such food.

Although ants are not dirty insects, they may sometimes walk across unclean areas during their foraging, this leads to them being considered unacceptable. When one foraging worker ant successfully locates a food source, they are able to communicate this information to their co workers which can lead to vast numbers of worker ants invading and contaminating human foods.

Prevention and control

Control measures should only be required where ants are invading or living in properties. To prevent invasion, good hygiene is essential. Always -

  • make sure all food waste and spillages are cleaned up immediately, keep foods sealed in tight fitting containers, especially sweet foods like sugar
  • avoid leaving pet food out for long periods
  • ensure that rubbish bins are emptied regularly

In case of invasion -

  • seal all cracks and crevices and other faults in the building with mortar/cement or mastic, as appropriate
  • these proofing measures should be supported by using a residual insecticide

Successful ant control using insecticides take a great deal of time and effort as nests are frequently inaccessible and difficult to destroy. For this reason, the best person to control the problem is often the occupier.

Using an insecticide - 

  • apply a continuous band of insecticide around all points of entry such as doors, windows, ventilators, ducts and drains to form a barrier both internally and externally. Re apply any external insecticide washed away by rain
  • treat all wall and floor junctions, ant runs and harbourages
  • give particular attention to small, insignificant cracks, which may be major points of entry for ants
  • regular treatments will be required and should start when you first notice the ants, normally in late spring
  • treat flying ants inside with a suitable aerosol insecticide


Some 'delayed action' insecticide baits can be very effective in destroying ants' nests. The worker ants transport the poison back to the nest, which is then destroyed. The main active ingredients are sodium tetraborate and trichlorphon. Suitable insecticides can be bought from most supermarkets, DIY stores and chemists.

Our pest control section carry out treatments for ants in industrial and commercial premises and domestic premises. 

Find out more about the cost of pest treatments 

Please remember that pesticides are toxic and the manufacturer's instructions must be followed at all times.

If you have any questions about the information contained in this leaflet or would like a treatment, please contact us on tel: 01482 300 300 20200127170346