There are 41 different species of ant living in the UK. The one that causes most problems for people is the garden or black ant (lasius niger), which is 4mm long and very dark brown to black in colour. Although they are not a health hazard, they can be a nuisance as they can find their way into homes in large numbers.

Black ants usually nest outdoors in lawns, flower beds, under paving stones, and in walls. Ants invade houses when they are attracted to sweet foods, getting in through small gaps in masonry, doors and windows. A trail of ants can usually be spotted making their way back to the ant nest.