Living in/under decking, concrete and brick laid areas the attractiveness is the sand used to create a base. To Garden Ants these areas are ideal to build substantial colonies in a relatively safe area whilst being within easy areas, waste bins.
Ant activity has Hygiene implications particularly regarding cross contamination of food and debris and can be a nuisance by sight and the continual presence particularly in ground floor areas can be disturbing. Treatments for garden ants can be various starting with Hygiene to proofing and moving to Insecticide and gel baits to remove the activity.