You probably grew up with your parents telling you, "Sleep tight and don't let the bed bugs bite." According to American Pest, bed bugs were a problem all the way back to the days of Ancient Rome. Bed bugs are opportunistic insects that come out at night to feed on the blood of their hosts. Bed bugs breed like rabbits and a female can lay thousands of eggs over the course of her lifetime. Even though only two North Dakota cities made the top 500, don't let that fool you.