Bed bugs typically feed on their preferred host, humans.
For thousands of years, humans understood that the bed bug would rather feed on humans than any other animal. Bed bugs only feed on blood; they do not feed on spilled food or other food of human origin.
When bed bugs feed, they insert their piercing and sucking mouthparts, injecting an anti-coagulant so that the host blood does not clot. The host does not feel the feeding process.
Little is understand about why bed bugs prefer to feed on one person and are less apt to feed on another. Most researchers think that a scent given off by humans as well as temperature and carbon dioxide will lead a bed bug to prefer one human over another. Blood chemistry and nutrition might also lead to a preference.
Adult and nymph bed bugs feed on blood. Both male and female bed bugs feed on blood and at least one blood meal is required for the bed bug to molt to the next stage of life.
Bed bugs are delicate and in the lab, bed bugs might not survive if they can’t feed directly on humans. Feeding devices to artificially feed bed bugs have been developed and even if using warmed human blood, the bed bugs might not as successful as those which feed directly on the human. Other animal blood can be used in artificial feeding but the blood might not sustain bed bugs.
When there is no human host available in the wild, bed bugs will feed on other mammals to survive. These can include rabbits, dogs, cats, and virtually any other warm blooded animal. There have been instances of feeding on birds. There are related insects which appear similar to bed bugs which feed on birds or bats. This is why it is always important to positively identify the insect.
Scientific literature from nearly a hundred years ago reports that bed bugs will feed even on cold blooded animals if no more preferred host is available. There are records that bed bugs have fed on lizards, a cold blooded animal. One study reports that bed bugs fed on other bed bugs if the bugs are held on warmed forceps.
Picture of a bed bug crawling on a human.
Human hosts cannot feel the feeding process.