Bed bugs (in Hong Kong also called chòuh chùhng / 臭蟲, “bed lice” / 床蝨, or wood lice / 木蝨) are small parasitic insects that feed on the blood of warm-blooded animals. The Centre for Health Protection (CHP) and the Food and Environmental Hygiene Department (FEHD) use 臭蟲 as the official Chinese name; residents more often say 床蝨 or 木蝨. Both the temperate bed bug (Cimex lectularius) and the tropical bed bug (Cimex hemipterus) occur in Hong Kong; their appearance and habits are similar, and control priorities are the same. This guide explains what they are, how to recognise them, and whether infestation means a home is “dirty.”
Scientific name and common names in Hong Kong
Bed bugs belong to the family Cimicidae (order Hemiptera), genus Cimex. Adults are about 4–5 mm long—roughly the size of a grain of rice—broad, flat and oval, reddish-brown, with no true wings. They cannot fly, but they crawl and hitch-hike on luggage, clothing, bedding and furniture. Glands on the thorax can produce an unpleasant odour; heavily infested rooms may have a faint smell.
In Hong Kong, 「臭蟲床蝨「木蝨」 usually refer to the same insect, not three different species. Use 「臭蟲」 when matching CHP/FEHD pages; 「床蝨」 is the everyday search and help-seeking term.
Appearance, life cycle and hiding places
Bed bugs undergo incomplete metamorphosis: egg, nymph and adult. Eggs are white and elongated, often stuck in cracks in bed frames, furniture, walls and floors; at about 1825°C they hatch in roughly a week. Nymphs look like smaller, paler adults and moult several times. Under suitable conditions the full life cycle takes about 6–8 weeks; adults may live 9–18 months and survive months without a blood meal.
By day they hide in dark, dry crevices: mattress seams, bed-frame joints, headboards, sofa seams, wallpaper edges, skirting boards, and similar spots. They more often feed at night or when people are still. Besides live insects, look for rusty faecal spots, pale cast skins, tiny eggs, and suspicious stains on sheets or pillows.
How to tell them from other insects? Can they fly?
Bed bugs do not fly. They spread mainly by crawling and by being carried on people and belongings. Busy places in Hong Kong—hotels, hostels, subdivided flats, public housing—are more exposed because of constant movement of people and goods.
Bites often appear on skin left uncovered while sleeping (face, neck, arms, hands), sometimes in lines or clusters. Bite marks alone cannot confirm bed bugs; you need environmental signs too. For bite symptoms see Bed bug bite symptoms; for DIY steps see How to treat bed bugs yourself.
Does infestation mean a dirty home? Do they spread disease?
Bed bugs prefer places where people sleep. There is no necessary link to a “dirty” household. Relatively tidy flats can still get them via travel luggage, visitors, second-hand furniture, or spread from nearby units. Early detection and action matter most.
According to CHP: there is currently no evidence that bed bugs (臭蟲) transmit disease. The main problems are disturbed sleep and itchy, swollen skin; heavy scratching can raise the risk of secondary skin infection. Do not describe bed bugs as disease vectors.
How to check whether you may have bed bugs
1. Use a torch to inspect mattress seams, the bed frame and headboard gaps. 2. Look for rusty spots, cast skins, eggs or an unpleasant smell. 3. Note whether bites are mostly on uncovered sleeping skin and recur in the same sleeping spot. 4. Recall recent hotel stays, second-hand sofas/mattresses, or pest control next door.
If you find signs, do not dump the mattress in the corridor (that spreads infestation). Isolate and clean first, then decide whether professional pest control is needed. FEHD also advises sealing cracks, limiting second-hand furniture, and regular vacuuming and washing of bedding to reduce harbourage and re-invasion. More steps: How to treat bed bugs yourself.
FAQ
Can bed bugs fly?
No. They crawl and are carried on luggage, clothing and furniture.
Are 臭蟲, 床蝨 and 木蝨 the same?
In Hong Kong they usually mean the same insect; officials say 蟲, residents often say 床蝨 or 木蝨.
Does having bed bugs mean my home is dirty?
Not necessarily. Cleaning reduces hiding places, but tidy homes can still receive insects from outside.
Do bed bugs spread disease?
CHP states there is currently no evidence that bed bugs transmit disease.
Must I throw away the mattress?
Not always. Try high-temperature washing of textiles, vacuuming and treating cracks first; dumping furniture carelessly can spread bugs to shared areas.