bed bug

Bed bug (Cimex lectularius). Photo: Whitney Cranshaw, Colorado State University,

Updated: December 21, 2023

About bed bugs

In recent years bed bugs have made a big comeback worldwide. They are especially bad in the mid-Atlantic area. Much of the blame for their resurgence as a pest has been globalization. People travel more internationally and more goods are shipped around the world than ever. Not only are bed bugs a problem in places such as hotels and hostels, but also in homes, hospitals, college dorms, and airports. It is important to familiarize yourself with what they look like, where to look for them, and what to do should you find them.

Bed bugs are insects that feed on blood. They are not known to transmit diseases. There are two types of bed bugs that may be found in association with people: the common bed bug, Cimex lectularius and the bat bug Cimex pilosellus.

  • Adults are light to reddish brown, oval, wingless, ¼ - 3/8” long before feeding.  After feeding they become bloated and dark red.
  • Eggs are very small, about 1/32” and found in clusters of 10-50.
  • Nymphs are colorless when they first hatch, but look like small adults.
  • All stages may be found in an infestation.
  • Bed bugs will bite all over the body, usually on exposed areas while a person sleeps. Reactions to bites vary by the individual person. Some people may not even know that they have been bitten, while others may develop painful swellings.

If you are traveling, check around the edges of the mattress, for blood spots, look under the edge of the head board, using a flash light if possible. Bed bugs tend to hide in areas that are not disturbed.  Never put suitcases on the floor or under the bed.  If you find them in your home or residence, do a thorough inspection of the area.  Get rid of clutter!  It is important to arm yourself with as much information as possible.

The following fact sheets go into great detail on biology and what to do if you discover that you have bed bugs.

Additional resource

Is Something Biting Me? | Penn State Extension