Bed bugs are a common concern, and many people wonder if these pests are exclusively active at night. While bed bugs are indeed primarily nocturnal, they can emerge during the day under specific conditions. Understanding their typical behaviors and the signs of their presence can help in identifying and addressing an infestation.
Understanding Bed Bug Behavior
Bed bugs (Cimex lectularius) are insects that feed on human blood. They are predominantly nocturnal, meaning they are most active during the night. This behavior allows them to feed on sleeping hosts undisturbed, as they are attracted to the carbon dioxide humans exhale and their body heat. Their peak feeding activity often occurs in the hours before dawn, typically between 2 and 5 AM.
Despite their nocturnal nature, bed bugs are opportunistic and will feed during the day if necessary. This can happen in cases of severe infestations where competition for blood meals is high, or if they are extremely hungry. If a host’s sleep schedule changes, such as with night shift workers, bed bugs will adapt their activity to feed when the host is inactive.
When not feeding, bed bugs hide in secluded spots close to their food source. Their flat bodies allow them to conceal themselves in tiny cracks and crevices. Common hiding places include mattress seams, box springs, and bed frames. They can also be found in furniture, behind picture frames, inside electrical outlets, and even in wall voids.
Identifying a Bed Bug Infestation
Recognizing the physical signs bed bugs leave behind is important for identifying an infestation. One of the most common indicators is the presence of bites on the skin. Bed bug bites often appear as itchy, red welts, which may be arranged in lines or zigzag patterns on exposed skin like the face, neck, arms, and hands. However, individual reactions to bites can vary, with some people experiencing delayed symptoms or no reaction at all.
Another key sign to look for is fecal spots, which are the excreted waste from digested blood meals. These spots appear as small, dark, rust-colored or black stains, resembling ink dots on bedding, mattresses, bed frames, or nearby furniture. They often bleed into fabric and can be found in clusters in areas where bed bugs hide or travel.
Shed skins, also known as exuviae, provide further evidence of bed bug activity. As bed bug nymphs grow, they must shed their outer exoskeletons. These discarded skins are translucent, hollow, and light tan or straw-colored, retaining the shape of the bed bug itself. Finding these varying sizes of shed skins indicates that bed bugs are progressing through their life stages within the infested area.
Bed bug eggs and egg casings are also indicators, though they are tiny and can be difficult to spot. Eggs are pearly white to pale yellow, oval-shaped, and about 1 millimeter long, similar in size to a pinhead or a grain of rice. Female bed bugs typically glue their eggs to surfaces in crevices. In cases of severe infestations, a sweet, musty odor, sometimes described as a “rusty” smell, may be noticeable due to pheromones, dead bugs, and accumulated fecal matter.