A bedbug is a tiny, flat insect that hides in mattresses, bed frames, and cracks in a room, then comes out at night to suck blood from people while they sleep. You often do not feel the bite at once; later you see small itchy spots, often in a little line. Older talk ties them to “dirty houses,” and crowded, neglected rooms do give them more places to hide — though actually they also turn up in clean homes and hotels, because they travel in bags, clothes, and furniture, not because someone failed to wash. They are hard to kill, which is why people speak of them with real dislike. The name is plain: a bug of the bed.

床蝨（口語也常說「臭蟲」）