Bed bugs are nocturnal pests that feed on the blood of humans and other warm-blooded animals. They possess highly developed sensory abilities, allowing them to detect humans. Understanding these abilities is important for combating infestations effectively.
How Bed Bugs “Smell” Their Hosts
Bed bugs do not possess a nose like humans, but they employ sophisticated biological mechanisms to sense their environment and locate hosts. Their antennae are equipped with specialized receptors for navigation and host detection.
These antennae house chemoreceptors, which detect chemical cues or odors in the air. Bed bugs also have thermoreceptors, allowing them to sense variations in temperature. These sensory organs enable bed bugs to detect subtle air currents, which can indicate exhaled carbon dioxide.
The Irresistible Cues for Bed Bugs
Bed bugs use their acute senses to pinpoint signals and substances emitted by humans. Carbon dioxide (CO2) is a primary long-range attractant, indicating a host’s presence. Humans exhale CO2, creating a plume bed bugs can follow. This gas signals the availability of a blood meal, prompting bed bugs to emerge from hiding spots.
Body heat is another important cue, acting as a short-range attractant. Once bed bugs are close, the warmth emitted by a human body guides them to the feeding location. Bed bugs are drawn to temperatures similar to human skin, typically between 70-80°F. Specific human odors and chemical compounds further enhance this attraction. These include certain fatty acids, ammonia, and other volatile organic compounds found in skin, breath, and sweat. Lactic acid, a component of human sweat, is particularly attractive to bed bugs, signaling a potential blood source.
Leveraging Scent for Bed Bug Management
Understanding bed bug sensory abilities has practical applications in detection and monitoring. One common method involves CO2-emitting traps. These devices mimic a sleeping person by releasing carbon dioxide, luring bed bugs out of hiding places and into a capture mechanism. Some traps combine CO2 with other attractants like heat or chemical lures to increase effectiveness.
Another application is training bed bug detection dogs. These highly trained dogs can pinpoint hidden infestations by recognizing the unique scent of bed bugs, including their alarm and aggregation pheromones. This method allows for detecting low-level infestations that might be missed by visual inspection.
While some strong scents, such as certain essential oils, are sometimes used as repellents, they are generally not effective against the attractants of CO2 and body heat. Bed bugs are primarily driven by the need for a blood meal, and these natural oils cannot consistently override their host-seeking behaviors.