The mere thought of going to bed and being bitten by just slightly larger than microscopic insets is enough to keep anyone up at night. Bed bugs average one millimeter to seven millimeters (or about 1/4 of an inch) in length yet they can wreak havoc on a person's life. Bed bugs only eat at night, usually right before daybreak. They hide in the bedding, furniture, and walls during the day. If there are just a few around, entomologists, or scientists who study bugs, say they will live closer to sleeping humans. However, if the colony grows, they will spread out around the house and find their living spaces in couches and chairs in the living rooms. A massive infestation of bed bugs emits a distinctive odor which is present throughout the house.