Key point in one sentence: “Bed bug”, “wood louse” and “stink bug” (床蝨／木蝨／臭蟲） are three names for the same insect — Cimex lectularius — so the control methods are identical and there is no need to research them separately.
The direct answer: 床蝨 (bed bug), 木蝨 (wood louse) and 臭蟲 (stink bug) all refer to the same insect — family Cimicidae, reddish-brown, flat-bodied, about 5–7 mm as an adult, emerging at night to feed on human blood. Anything you find online about getting rid of “wood lice” or “stink bugs” in a Hong Kong home context applies to bed bugs, because it is the same pest. The names differ only in who uses them, and since when.
Where the three names come from
| Name | Where it is most used | Why the name |
|---|---|---|
| 床蝨 (bed bug) | The mainstream term in Hong Kong daily speech and media; by far the most searched of the three | It hides in mattress seams, bed frames and headboards by day and bites at night — the bed is its home ground |
| 木蝨 (wood louse) | The older generation’s term in Hong Kong; younger people rarely use it now | When furniture was mostly wooden, they favoured the cracks of wooden bed boards and wooden furniture |
| 臭蟲 (stink bug) | The standard term in mainland China and Taiwan; Hong Kong official documents use it too | When startled or crushed, it releases a pungent fluid from scent glands; Cimicidae is also literally the “stink bug family” in Chinese |
Hong Kong’s Centre for Health Protection uses 床蝨 (“Bed Bugs”) on its topic page, and the Food and Environmental Hygiene Department publishes home bed-bug prevention guidelines. Whichever name you use, it is the same insect and the same treatment.
Careful: “wood louse” has a second meaning
Search “木蝨” online and you may land on pages about fruit trees and houseplants. Those are about the family Psyllidae — the jumping plant lice. These true “wood lice” are 2–5 mm plant-sap feeders that live on fruit trees and ornamental plants. They do not bite people and do not live indoors; they are garden pests with no relation to the bug in your bed. For the biting household pest, “bed bug” （床蝨） is the precise search term.
The look-alikes, separated in one table
| Creature | Size | Bites people? | Where found | One-line difference |
|---|---|---|---|---|
| Bed bug (= 木蝨／臭蟲） | Adult 5–7 mm, apple-seed sized, clearly visible | Yes — feeds on blood | Mattress seams, bed frames, sofa edges | Lines or clusters of bites, plus dark faecal spots and shed skins near the bed |
| True wood louse (Psyllidae) | 2–5 mm | No — feeds on plant sap | Undersides of leaves on trees and plants | Only ever found on plants |
| Dust mite | ~0.3 mm, invisible to the naked eye | No — eats skin flakes; its droppings trigger allergies | Mattresses, pillows, carpets | No bites, but morning sneezing and nasal allergy |
| Booklouse (塵蝨） | ~1 mm | No — eats mould | Damp walls, books, stored grains | Specks like dust; a sign the home is too humid |
| Flea | 2–3 mm | Yes — usually around the ankles | Pets, carpets | It jumps away when you try to catch it; bed bugs cannot jump |
How to confirm the bug at home is a bed bug
Forget the name — check three things:
- Appearance: reddish-brown, flat and oval, wingless, about the size of an apple seed; after feeding it swells and turns darker red.
- Traces: dark brown-black specks (faeces) and pale shed skins along mattress seams and bed-frame joints; blood spots on sheets in heavier infestations.
- Bites: noticed on waking, on exposed skin (arms, neck, face), in lines or clusters, itchy for one to two weeks. See the bed bug bite identification guide for detail, and the life-cycle guide for how they grow from egg to adult.
FAQ
Which name is the “correct” one — bed bug, wood louse or stink bug?
None is more correct than the others — there is only one scientific name, Cimex lectularius. Hong Kong searches and media favour 床蝨， 臭蟲 is the standard term in mainland China and Taiwan, and 木蝨 is the older local word. Pest-control companies and pharmacies understand all three.
Is a bed bug the same as the stink bug in the garden?
No. Garden stink bugs (family Pentatomidae) are shield-shaped plant feeders that do not bite people. Bed bugs belong to Cimicidae: wingless, unable to fly or jump. Only the word “stink” overlaps.
If I was bitten by a “wood louse”, is the treatment the same as for bed bugs?
Yes — it is the same insect. Wash the bites with soap and water, avoid scratching, and the itching usually settles within one to two weeks. See a doctor if there is widespread swelling, blistering or signs of infection, as Hong Kong’s Centre for Health Protection advises.
What if I can’t tell whether it’s bed bugs or dust mites?
A visible 5–7 mm insect plus bites plus faecal spots by the bed means bed bugs. If you can see nothing and only have morning nasal allergy and itching, it is more likely dust-mite allergy — the fix is hot-washing bedding, mite-proof covers and humidity control, not insecticide.
Need a company to handle it?
If you have confirmed bed bugs and cannot clear them yourself, see our Hong Kong pest control directory: 46 companies in three tiers, each with a tap-to-call phone number.
Sources: Centre for Health Protection “Bed Bugs” topic page; Food and Environmental Hygiene Department home bed-bug prevention guidelines; Wikipedia, “Psyllidae”.