How do bedbugs bite people? - briefly
Bedbugs pierce the skin with a slender proboscis, inject saliva that contains anticoagulants and anesthetic compounds, and then withdraw to ingest blood. The bite typically appears as a small, red, itchy welt, often in clusters where the insects feed during nighttime.
How do bedbugs bite people? - in detail
Bedbugs (Cimex species) feed by inserting a slender, needle‑like mouthpart called a proboscis through the epidermis. The proboscis consists of two stylets: one functions as a needle to pierce the skin, the other acts as a channel for saliva. When the stylet reaches a blood vessel, the insect releases saliva that contains anticoagulants, vasodilators, and anesthetic compounds. These substances prevent clotting, widen the capillary, and temporarily numb the area, allowing the insect to draw blood uninterrupted.
The feeding sequence proceeds as follows:
- Attachment – the insect climbs onto the host’s exposed skin, typically during the night when the host is immobile.
- Penetration – the outer sheath of the proboscis punctures the epidermis, guided by sensory receptors that locate a suitable blood vessel.
- Saliva injection – a minute volume of saliva is deposited into the wound; the cocktail of bioactive proteins inhibits platelet aggregation and reduces pain perception.
- Blood extraction – a peristaltic motion of the cibarial pump draws blood up the inner stylet and into the gut. Each bite generally yields 0.1–0.5 µL of blood.
- Detachment – after feeding for 5–10 minutes, the bug withdraws its mouthparts and retreats to a hiding place.
The bite itself leaves a puncture mark that is often invisible to the naked eye. The anesthetic effect may delay the host’s awareness, so the lesion appears later as a small, red, raised welts. In some individuals, the immune response to salivary proteins produces itching, swelling, or secondary infection if the area is scratched.
Key factors influencing the reaction include:
- Host sensitivity – allergic individuals develop larger, more inflamed lesions.
- Feeding frequency – repeated bites in the same area can amplify the inflammatory response.
- Saliva composition – variations among species affect the potency of anticoagulants and allergens.
Understanding this process clarifies why bedbug bites are often painless at the moment of feeding yet become noticeable hours later as a localized skin reaction.