Cimex lectularius Surveillance Method

Bed bugs are small, parasitic insects that are reddish-brown in color and feed on the blood of humans and animals at night. Look for physical signs of bed bugs to identify a possible infestation.

When cleaning, changing bedding, or staying away from home, look for: rusty or reddish stains on bed sheets or mattresses caused by bed bugs being crushed; dark spots which are bed bug excrement and may bleed on the fabric like a marker would; eggs and eggshells, which are tiny (about 1mm) and pale yellow skins that nymphs shed as they grow larger; live bed bugs. When not feeding, bed bugs hide in a variety of places. Around the bed, they can be found near the piping, seams and tags of the mattress and box spring, and in cracks on the bed frame and headboard. If the room is heavily infested, you may find bed bugs: in the seams of chairs and couches, between cushions, in the folds of curtains; in drawer joints; in electrical receptacles and appliances; under loose wall paper and wall hangings; at the junction where the wall and the ceiling meet.

EPA
Additional Links:
https://www.epa.gov/bedbugs/how-find-bed-bugs
https://www.cdc.gov/parasites/bedbugs/faqs.html