Field plate · Cimex lectularius
Bed bug
Flat, apple-seed-sized, and year-round in rental stock, hotels, and second-hand furniture. Identification is by the bug or its traces — never by bites alone.
Plate 1 of 28. Drawn in profile to the identification marks named below; the scale rule is a drawing convention — sizes are given in the text.
Identification marks
An unfed adult is flat, oval, rusty brown, about 5–7 mm, with horizontal banding on the abdomen; after feeding it swells and reddens. Eggs are 1 mm, white, glued in seams. Black fecal spots on mattress piping are the commonest trace.
Look-alikes it is confused with
Bat bugs (microscopically different, tied to bat colonies), swallow bugs, carpet beetle larvae (hairy, and in the bed only by accident), and — most often — anxiety over fleas, scabies, or dermatitis. Bites alone identify nothing.
Where it hides in a house
Mattress seams and piping, bed-frame joints, headboards, baseboards behind the bed, sofa seams, and the luggage and laundry routes between rooms. In rentals: the bed, then the couch, then the unit next door.
Health & property risk, stated plainly
No disease transmission is established for bed bugs. The real harms are itching and lost sleep, secondary skin infection from scratching, the cost of treatment, and the strain of a long infestation — which should be named plainly rather than dismissed.
What actually works
Inspection first, then a prepared program: encasements, laundering and high-heat drying of textiles, clutter reduction around the bed, interceptors under bed legs, and either professional heat treatment or a careful multi-visit insecticide program. See the methods page on heat.
What doesn't
Bug bombs — they scatter bed bugs into walls and adjoining rooms and are a documented cause of whole-building spread. Also: throwing out the mattress before treatment (bugs simply relocate), and alcohol or kerosene sprays, which are fire hazards.
Found one tonight — the first 24 hours
Do not move to the couch, and do not change rooms: sleeping elsewhere spreads the infestation to a second hiding place and doubles the treatment. Stay in the bed; the bugs are already there, and interceptors under the bed legs (fitted tomorrow) will prove it. Isolate the luggage: suitcases and travel bags go into the bathtub or a sealed bag, away from the bed — never onto another bed. Hot-wash and hot-dry bedding and worn clothing (the dryer’s heat does the work), and bag cleaned items sealed until the room is cleared. Photograph and save a specimen in a sealed jar — identification decides everything that follows. If you rent, notify the landlord promptly and in writing (dated, kept copy), and do not throw out the mattress: it spreads bugs down hallways and stairwells, and a treated, encased mattress is a better outcome. Then book the inspection; preparation lists come from the operator who has seen the room.
When to call a licensed pro
Yes. Bed bugs are the clearest call-a-pro pest on this desk: the inspection, preparation, and follow-through decide success, and in rental housing the work has to be coordinated across units.