What you are actually looking for
Bed bugs (Cimex lectularius) are visible to the naked eye. An adult is approximately 5 to 7 millimetres long, flat, oval, and reddish-brown when unfed. Fed adults are darker and more elongated. Nymphs (juveniles) are translucent to pale yellow and much smaller, but still visible in good light. You are looking for four things in order of reliability: live or dead insects; dark brown fecal spotting (roughly the size and colour of a felt-tip pen dot); cast skins, which are translucent shed exoskeletons; and blood staining on fabric.
The fecal spotting is the most reliably present sign even in light infestations. It appears as clusters of small dark spots, often smeared slightly where the bug moved after defecating, concentrated at harborage sites. Once you have seen bed bug fecal spotting in person, you will not confuse it with anything else. Dirt spots are scattered. Fecal spotting appears in clusters with a slightly raised, waxy texture on smooth fabric.
The inspection protocol
Five-minute hotel bed bug inspection
The exact protocol used by professional bed bug inspectors when auditing hotel rooms, simplified for the travelling guest.
- 1Leave luggage in the bathroomBefore touching anything in the room, move all soft luggage into the bathroom and leave it on the tiled floor or in the bathtub. Bathrooms are almost never harborage sites. This keeps your belongings clean while you inspect.
- 2Pull back the headboard corner firstThe junction of the mattress seam at the headboard end is the single highest-probability location for bed bugs in a hotel room. Pull the mattress corner back 20 to 30 centimetres and examine the piped seam, the box spring surface, and any visible box spring fabric with your flashlight. Look for dark spotting, skins, or live insects.
- 3Check the other three mattress cornersRepeat the pull-back on all four corners, spending 20 seconds at each. The foot-end corners are lower risk than the headboard end but are the location for secondary clusters in moderate infestations.
- 4Inspect the headboard itselfMost hotel headboards are mounted to the wall with brackets or channels. Pull the headboard away from the wall two to three inches and shine your light into the gap. This void is a primary harborage site. Look for spotting on the wall behind it and on the back face of the headboard.
- 5Check upholstered furniture seamsIf the room has an upholstered chair or sofa, run your fingers under the seat cushion front edge and check the fabric piping at the back. Secondary infestations in hotel rooms frequently involve an armchair that has been in the room longer than the current mattress set.
- 6Inspect the luggage rackLuggage racks with fabric straps are a frequently overlooked harborage point. Quickly check the strap weave and the junctions between the strap and the metal frame. Keep your luggage off fabric-strap racks as a precaution.
- 7If in doubt, request a room changeAny sign of spotting, skins, or insects is grounds for a room change without argument. Most front desks at reputable properties will accommodate the request immediately. Do not continue to use the room while awaiting confirmation — remove yourself and your luggage.
The three mistakes most travellers make
The first mistake is only checking the mattress surface. Bed bugs do not typically live on top of the mattress; they live in the seams, folds, and voids adjacent to the mattress. Pulling back the corner rather than just lifting the top sheet is the difference between a useful inspection and a theatrical one.
The second mistake is using only ambient room light. The overhead lighting in hotel rooms is designed to flatter the space, not to illuminate the inside of mattress seams. A small flashlight or the torch mode on a smartphone is non-negotiable for a meaningful inspection. Direct light at the right angle produces reflective highlights on cast skins and catches the sheen of fecal spotting that flat overhead light misses entirely.
The third mistake is waiting until the last night to check. The purpose of the inspection is to make a decision about whether to stay or move rooms, not to document what you found after six nights of exposure. Check on arrival, before your belongings have entered the room.