Why do bed bugs bite but are not visible? - briefly
«Bed bugs feed on blood during the night, injecting anesthetic and anticoagulant that conceal the bite». Their minute, flattened bodies and nocturnal hiding in mattress seams and furniture crevices keep them out of sight until infestations become noticeable.
Why do bed bugs bite but are not visible? - in detail
Bed bugs (Cimex lectularius) feed exclusively on blood, inserting a needle‑like proboscis into the host’s skin. Saliva contains anticoagulants and anesthetic compounds, which prevent immediate pain and allow the insect to withdraw unnoticed. The bite itself is a small puncture that often leaves only a faint, red welt after several hours.
The insects remain hidden because adult individuals measure 4–5 mm in length, resembling a small seed. Their flattened bodies enable them to slip into narrow crevices, mattress seams, upholstery folds, and electrical outlets. Nocturnal activity reduces exposure to daylight, while cryptic coloration matches the fabrics they inhabit. These traits together make visual detection difficult without thorough inspection.
Salivary proteins trigger an immune response that typically manifests 12–48 hours after feeding. The delayed reaction obscures the link between the bite and the feeding event, leading many to overlook the presence of the pest. Moreover, only a few insects are required to produce noticeable bites, further complicating identification.
Effective detection relies on systematic examination of common harborages: mattress edges, box‑spring seams, headboards, and cracks in furniture. Tools such as magnifying lenses, flashlight beams, and interceptors placed under legs of beds can reveal live bugs, shed exoskeletons, or fecal spots. Tracking devices that monitor heat and carbon‑dioxide emissions also assist in locating active colonies.
Control strategies combine mechanical, chemical, and preventive measures. Mechanical actions include vacuuming, steam treatment, and laundering infested fabrics at temperatures above 60 °C. Chemical options comprise approved insecticides applied to cracks and crevices, while integrated pest‑management protocols recommend regular monitoring to confirm eradication. Preventive practices involve encasing mattresses, reducing clutter, and inspecting second‑hand items before introduction into living spaces.