Social insects which may live in communities of many millions of individuals. In tropical and sub-tropical countries they are major pests of timber buildings.
Not presently a significant problem in the UK but global warming may allow them to establish in the south of England.
Also known as “thunder-flies”, very small (1.5mm) insects, black with narrow hairy wings. They feed on plant sap and on humid summer days they may occur in huge numbers on window sills and getting into clothing and hair.
An agricultural pest, they are only a nuisance in domestic premises. They have been known to trigger fire alarms by collecting in large numbers inside smoke detectors.
Closely related to the mites, but much larger and reliant on vertebrate blood. They are occasionally brought into the house on domestic animals and can be picked up by humans after walking through long grass in an infested area.
Ticks are implicated in the transmission of Lyme disease and medical advice should be sought if a rash appears at the site of a bite. Remove them with a twist to avoid leaving the mouthparts in the skin.