Bed bugs have a cryptic lifestyle, meaning they spend the majority of their time hiding together in cracks and crevices where they will not be seen or disturbed. However, they become active at night, between midnight and 5:00 am. It is during this time, when the human host is typically in their deepest sleep, that bed bugs like to feed.
Bed bugs are known to travel many yards to reach their human host. Bed bugs are attracted to CO2 produced by the host exhalations, and they are also attracted to body heat. However, bed bugs are only able to detect these host cues over short distances (about 3 feet away for CO2 and even less for heat).

 It is not well understood how bed bugs hiding in a closet are able to find a host located in a bed across the room. However, bed bugs are able to move very quickly, and it is thought that they do a lot of wandering around before they are able to locate their food. Ideally, most bed bugs would like to aggregate near the host’s bed, on the mattress or in the boxsprings, when they are not feeding. However, this is not always possible in heavy infestations where bed bugs are crowded and many bed bugs have to seek refuge at distances several yards from the host.

Photo - courtesy of Kim Jung