The answer to this question depends on what the questioner meant by it.  In terms of overall habitat, bed bugs live in every continent on earth except for Antarctica.  That said, they tend to thrive in tropical or temperate environments; very cold climates slow down their life cycles and help to retard the incidence of serious infestations.

Bed bug infestations are a growing problem in certain areas of the world.  These include Europe, North America, and Central Asia.

If, however, the questioner meant to ask where in a house bed bugs tend to live, the answer must be much more detailed.  As the name suggests, bed bugs are most commonly found in bed mattresses and bed frames because they are attracted to warm blooded mammals. They can located anywhere in a home because bed bugs can thrive in so many different hiding places.  What all of these places tend to have in common is the presence of folds, creases, seams, or crevices.  These are ideal locations for bed bugs to lay their eggs; the bugs themselves may also adhere to these areas when not crawling forth at night to bite unsuspecting sleepers.

The most common locations that meet the criteria described above are beds and upholstered furniture, with the seams of mattresses being an overwhelmingly popular place for bed bugs to infest.  However, the bug cannot thrive unless there is a host present to provide blood.  This host may be a human being or any other warm-blooded mammal.  Pets or other types of animals that may be present in the home, such as mice, can function as hosts.

However, a vacant apartment can still be infested by bed bugs, even in the absence of any host at all.  This is because bed bugs can enter a dormant state and stay that way for many months or even years.  This is why simply abandoning a habitation for a time is not a good solution for dealing with bed bugs.  Not only can the bugs simply go dormant, but if there are any hosts in contiguous apartments, they may simply move next door and move back again once they sense the presence of a host in the original dwelling they had temporarily abandoned.

Dealing with an infestation requires diligent effort, the right products and techniques, and often, the services of a professional exterminator.  Those topics will be explored in further articles.