Bed bugs are nocturnal, so turning off the lights makes them more likely to come out to look for prey.
Bed bug bites can be red and itchy, and they are often in a line or cluster. Some people may have an allergic reaction to the bites.
The critters can be dark yellow, red or brown and generally only about 5mm in length while eggs are usually white in color.
If tourists can’t see the bugs, they may look for red or rusty spots on the mattress, which could be a squashed bug.