1. Live Bed Bugs – The only reliable indicator of an active bed bug infestation is the presence of live bed bugs. Finding dead bed bugs or any of the other signs below means that there might have been (or may still be) a bed bug infestation. If you find other evidence, but not live bed bugs, you need to inspect further to find out if you do indeed have a bed bug infestation.

2. Dead Bed Bugs or Shed Skins – Both are indications that there either still is, or there once was, a bed bug infestation. In order to grow, a bed bug nymph must molt or shed its skin. The empty shed skins will be found in places where bed bugs hide. But be careful that you don’t confuse the shed skins of cockroach nymphs or carpet beetles with those of bed bugs.

3. Fecal Spots – The digested blood in the gut of a bed bug is deposited as semi-liquid black poop. As the liquid drops dry, they leave behind a black, slightly raised spot. Cockroach fecal spots look similar but if you wet a bed bug fecal spot, it will smear, while a cockroach’s fecal spot will not. You might see large numbers of fecal spots in places where bed bugs hide together such as along the seams of a mattress. There’s no easy way to tell whether bed bug fecal spots are old or new.

4. Blood Spots – Blood spots are not the same as bed bug fecal spots. They are brown or red-rusty spots found on sheets, pillowcases, clothing, and sometimes on the wall behind the bed. Some of these blood spots drip out of the anus of the bed bug just after it finishes feeding, and some are blood spots that drip from the bite wound of the victim. Bloodstains on bedding are not, by themselves, indicative of a bed bug infestation since other liquids leave rusty stains and bloodstains do not easily wash out so you can’t estimate age.

5. Bed Bug Eggs – Bed bug eggs are most noticeable when they are in clumps in places where bed bugs hide, but they can be found individually even far from the bed. The eggs are small, translucent white, and can be seen with the naked eye although they are usually hidden in crevices or holes. They are attached to surfaces with a sticky substance. Eggs that have either hatched or won’t hatch are dried up or shriveled while viable eggs are white and plump.

6. Bed Bug Bites – I hesitate to even mention this possible sign since bed bug bites are so variable from individual to individual and so many things can cause what appear to be bites. On average, a bed bug will feed on human blood about every 3 days. Bites are generally pain-free. Time to reaction ranges from almost immediately to 7-11 days. Reactions after the bite range from none at all to swelling and severe itching. Needless to say, the appearance of bites when the bed bug is not seen, is not conclusive evidence of an infestation.