Bed bugs are a nasty nuisance, and are often misunderstood. They spread by attaching themselves on to anything with a nook (like your shoe), and once in your home, readily reproduce. Bedbugs hide in crannies like cracks in your wall, screw holes, and the crease of your mattress. They hate being left out in the open.
Many store bought bed bug killers are not effective. Treatments such as foggers only work if the poison comes in direct contact with the bed bug, which, due to their small size, is highly unlikely. You must kill every single bed bug in your house in order to get rid of the problem, and if one male and one female remain, the infestation will soon return.
It is a common misconception that bed bugs spread disease, and are found only in low-income homes. Bed bugs do not spread disease, and can be found anywhere. Having bed bugs is highly stigmatized, and people may hide the fact that they have bed bugs in their home from visitors or landlords. Having bed bugs is simply bad luck! Tell your landlord immediately, and contact a pest management professional. Bed bugs will continue to spread until they are destroyed. The most effective method is a heat treatment, which, unfortunately, can be expensive. Drying clothes and sheets with bedbugs in your clothes dryer can also kill them.