Bed Bugs are blood suckers. Blood is there main and only source of food. Unlike other insects, bed bugs prefer feeding on humans. Carbon dioxide and body warmth are the two man reasons why bed bugs are attracted to us.
When bed bugs feed, they pierce the skin of their victims with two hollow feeding tubes. The first one is simply to release anesthetic to “numb” the feeding area. (This is why it is almost impossible to tell when they are actually feeding on you). The Second tube sucks up the blood from their victim. Bed bugs will often feed for about 5 minutes and then they will return to their nest or a tight warm place.
Bed bugs can live without food for about a year. Although, they often feed every 5 to 10 days.