The bed bug (Cimex lectularius) is a small, parasitic insect that feeds exclusively on the blood of warm-blooded hosts, most often humans. These pests do not live on a host but emerge from hiding spots to take a blood meal, typically at night while a person is sleeping. Bed bugs do not eat every night; their feeding schedule is irregular and driven by biological needs rather than a daily requirement. While their survival and reproductive cycles depend on blood meals, the frequency is highly variable and influenced by environmental conditions.
The Bed Bug Feeding Cycle
A bed bug typically feeds once every 5 to 10 days. This interval can be shortened, particularly for female bed bugs, which may feed every two or three days to support egg production. Regular access to blood meals significantly boosts a female’s reproductive output, allowing her to produce between one and seven eggs per day for about ten days following a single meal.
The insect’s life stage also determines feeding frequency. Immature bed bugs, called nymphs, must take at least one blood meal to successfully molt and progress through their five developmental stages. Under optimal conditions, a nymph may progress through a molt within five days of feeding, requiring a new meal to continue its growth. Warmer temperatures increase the insect’s metabolism, leading to a faster feeding cycle and quicker development from egg to adult, sometimes taking as little as 37 days.
The Mechanics of a Blood Meal
Bed bugs are nocturnal feeders, usually becoming active between midnight and 5:00 a.m. when a host is in their deepest sleep. They locate a host by detecting heat and the carbon dioxide exhaled during breathing. Once a suitable spot on the skin is found, the bed bug uses its specialized mouthpart, the proboscis, to pierce the skin.
The insect injects saliva containing both an anesthetic, which numbs the bite area, and an anticoagulant, which prevents the blood from clotting. This combination allows the bed bug to feed unnoticed by the host. A full blood meal typically lasts between three and 12 minutes, during which the insect becomes visibly engorged. The appearance of multiple bites in one area often occurs because the bug may probe the skin several times to find a capillary that provides a rapid flow of blood before settling down to feed.
Survival Without Feeding
The resilience of the bed bug is demonstrated by its ability to survive long periods without a blood meal, a trait that makes them difficult to eliminate. Bed bugs can survive by significantly lowering their metabolic rate, effectively entering a dormant state to conserve stored energy. This mechanism allows adult bed bugs to survive for several months without feeding, even under normal room temperatures.
The length of time a bed bug can survive is heavily dependent on the ambient temperature. In cooler environments, such as around 50°F, their metabolism slows down further, and adults have been known to survive for over a year. Younger nymphs are the most vulnerable life stage, requiring blood to molt and generally surviving for only a few weeks without a meal. This remarkable ability to endure prolonged starvation periods is why simply vacating an infested property for a short time is often ineffective in eliminating a bed bug infestation.