Ants

Symptoms
Ants are a nuisance rather than destructive pests. They look for the sweet liquid known as honeydew which is excreted by aphids and some other sap-feeding insects. Ants protect aphids from attack by ladybirds and other predators in order to secure their supply of honeydew. Increased numbers of aphids may result in more damage to plants.

Spot them
All ants live in nests which generally contain large colonies of wingless female workers. Winged males and fertile females are produced occasionally swarming in mating flights.