All About Bed Bugs
Bed Bugs are small insects that are highly specialized in what they do. They have particular habits and behaviors that are critical to their survival, and which can make them a challenging pest to eliminate. Knowledge is the key, as only by understanding every aspect of the behavior and biology of Bed Bugs can we create the tools we need to combat them.
Knowing the Enemy
Bed Bugs are small, cryptic, nocturnal insects that live by feeding on the blood of warm-blooded animals – with a strong preference for people. They are closely related to other species of bugs that specialize in feeding on bats and birds, and are thought to have evolved from a bug that preyed on cave dwelling bats or pigeons. Bed Bugs are wingless in all stages of development, gregarious, almost social animals, that like to be in contact with each other when resting, and prefer living in tight spaces such as cracks.
Adult Bed Bugs are about four millimeters long, flattened “top-to-bottom” (an advantage when living in cracks), and usually dark brown in color due to the blood meal contents of their gut. Nymphs are considerably smaller, to the point of being difficult to identify with the naked eye. They are normally only active outside their resting area when they feed, which is usually in the early hours of the morning when it is dark and quiet. They do not spend long periods on their host other than to feed.
As adults, Bed Bugs will feed about every third night, and will often return to the same location and host. As soon as a Bed Bug begins to feed it produces a “sweet sickly” odor from glands at its anal end. This acts as a stimulant to other Bed Bugs, causing them to increase their activity in search of food.
Bed Bugs consume a considerable amount of blood at each feed (proportionate to their size), and swell during feeding. This size increase would prevent the Bed Bug from returning to their preferred resting cracks, so they excrete the excess water from their meal, retaining only the nutrients and solids. This excreta causes black sticky marks to be left by feeding Bed Bugs near their daytime resting area.
Surprisingly, these marks are often the first signs that Bed Bugs are even present. To avoid retaliation from the host, Bed Bugs inject an anesthetic through their mouthparts before starting to feed, so the host is usually unaware of any feeding activity. This, and their very secretive behavior, can allow Bed Bug populations to develop into significant numbers before treatment is even considered.
Bed Bugs can survive for long periods without feeding – over a year under some circumstances. Feeding by Bed Bugs may also be seasonal in unheated premises, as they enter a type of hibernation if the temperature drops below 13 degrees Celsius for any extended time.
Bed Bug problems are notorious for “appearing out of nowhere”. This is due to a number of factors:
• Bed Bugs are cryptic. Small populations are rarely evident, and even considerable populations may remain undetected for long periods.
• When provided with a suitable environment, Bed Bugs are prolific. Under perfect conditions of temperature and food availability, a population of 40 Bed Bugs could potentially grow to over 5,900 within six months.
• Bed Bugs are socially undesirable and often associated (quite erroneously) with poor hygiene. This “social stigma” slows the implementation of effective treatment, giving time for existing Bed Bug populations to spread. Bed Bugs are surprisingly mobile, and have been found to move easily between units in multiple family structures, as well as traveling considerable distances through pipes, drains, and even outside along brickwork.
At least 28 human pathogens have been demonstrated to occur naturally in Bed Bugs. However, there has never been a single case where Bed Bugs have been proven to be the causal vector of a disease. Some people have reported serious asthma-like symptoms resulting from exposure to Bed Bugs and the cast skins of Bed Bug nymphs, and these are believed to be an allergic response caused by sensitivity to the chitin or other compounds they contain.
More serious than the disease potential is the plain discomfort suffered by those bitten by Bed Bugs, both physically and psychologically. Physically, the bites cause a wide variety of reactions from mild itching to rashes, widespread weal’s and significant distress. Psychologically, there is no one immune from the very real fear of being “eaten alive” by Bed Bugs while they sleep, and few people in developed nations who can avoid at least some social discomfort, however undeserved.