Bed bugs occur in all regions of the globe.[7] Rates of infestations are relatively common, following an increase since the 1990s.[3][4][6] The exact causes of this increase is unclear; with proposals including greater travel, more frequent exchange of second-hand furnishings, a greater focus on control of other pests, and increasing resistance to pesticides.[4] Bed bugs have been known human parasites for thousands of years.[2]
 Adult bed bugs are about 3/16” long and reddish-brown, with oval-shaped, flattened bodies. They are sometimes mistaken for ticks, cockroaches, carpet beetles or other household insects. The immature bed bugs (nymphs) resemble the adults, but are smaller and lighter in color. Bed bugs do not fly, and they don’t jump like fleas do ― but they can crawl rapidly over floors, walls, ceilings and other surfaces. Adult females lay their eggs in secluded places, depositing 1, 2 or more eggs per day, potentially hundreds during their lifetime. The eggs are tiny (about the size of a dust spec), whitish and hard to see without magnification, especially on light-colored surfaces. When first laid, the eggs are sticky, causing them to adhere to surfaces. At room temperatures, bed bug eggs hatch in about a week. Newly emerged nymphs are straw-colored and no bigger than a pinhead.
The size of bed bug bites varies with a number of different factors. Bed bugs inject an anti-coagulant along with their saliva when they pierce the skin to take a blood meal. This anti-coagulant is mostly responsible for how a person reacts to the bite and determines the size of the bug’s bite. Since people will have various sensitivities to the bed bug’s bite, the size of the bite will vary, as well. Another factor that influences the size of a bed bug reaction is the number of times a person is bitten. Bite reactions of people bitten many times are also variable, and their response may be either more or less intense as the number of bites increases.