Bed bugs are small parasites that feed on blood and are often found in groups. Their preferred hiding spaces include beneath mattresses, within bedding and in other sleep areas. Bed bugs are most active at night and can multiply extremely fast. Unlike roaches, they don’t thrive in dirty environments and aren’t attracted to food that’s been left out. No building is safe from bed bugs. If you’ve found mysterious bite marks along your body, you may have a bed bug problem.