Bedbugs are one of the true ‘bugs’, that is, they are insects belonging to Order Hemiptera.  Hemipterans all have piercing and sucking mouthparts, and the vast majority of them suck sap from plants.  A small proportion of the bugs are ectoparasites of animals, including those belonging to Family Cimicidae, one of which is the bedbug (cimex lectularius).

The activity of bedbugs in premises is usually detected by irritation caused to sleepers, although blood spots on the sheets may be the first indication.  In infested premises, evidence of activity can include: live bugs hiding in cracks and crevices in furniture, behind wallpaper, in bedding, especially in grooves and alongside piping in the mattress, and in other harbourages; eggs cemented to similar surfaces; cast skins; small dark-brown excreta marks on sheets, walls and other surfaces and, in the case of heavy infestation, a sickly sweet ‘buggy odour’.   This odour is caused by body secretions, but may be masked by other odours prevalent in unclean premises.