Adult bed bugs are flat, oval, wingless creatures with segmented bodies and three pairs of legs. They are dark red or brown in colour and 1-5mm in length. They are not to be confused with the Martin bug which is similar in appearance but pale yellow in colour and approximately half the size of the bed bug.
Adult bed bugs live up to four years or more and normally live and breed in the cracks and crevices of the building e.g. behind loose fitting wallpaper, cracks or grooves in woodwork, cracks in plasterwork, wooden battens, damaged floorboards or possibly behind ornaments and permanent fittings. They may also be found in furniture e.g. buttons or stuffed leather, mattresses, hollow brass-work in bedsteads, the underneath of chairs, folds in the tops of curtains, bedding and undisturbed trunks or boxes.
Bed bugs are generally nocturnal in habit and feed only on the blood of mammals and birds. Although they are capable of existing without food for up to six months they will feed on average once a week depending on temperature and food availability.
The eggs of the bed bugs are yellowish white in colour and approximately 0.5mm in length and 0.2 mm in diameter. Under normal conditions the female will lay from 100-200 eggs at irregular intervals. These will normally hatch between one and three weeks later, although this can be longer.
Young bed bugs (nymphs) will hatch from the eggs and begin feeding immediately. Nymphs are much smaller than adults, approximately 1mm in length and are round with red eyes. As they grow they become darker and flatter. They will also shed their skins on several occasions to accommodate their growth.
Bed bug infestation may be detected by the musty, sour, unpleasant smell which is invariably present when a room is heavily infested. Their presence may also be detected by minute black droppings which can be found in any of their hiding places previously mentioned. Small blood stains on the pillow case or bedding may result when a bed bug is squashed. Humans which have been bitten may have a number of small marks or spots on their skin, usually on the feet, arm or neck.