How do human fleas bite? - briefly
Human fleas attach to the host, pierce the skin with specialized mouthparts, and inject saliva containing anticoagulant compounds, creating a tiny, itchy wound. The bite manifests as a red papule that can develop a small scab if scratched.
How do human fleas bite? - in detail
Human fleas (Pulex irritans) attach to the host’s skin with specialized mouthparts. The process proceeds through several distinct phases.
- The flea locates a suitable feeding site by detecting heat, carbon‑dioxide, and movement.
- The insect raises its hind legs, anchors them on the epidermis, and extends the head toward the skin surface.
- The maxillae and mandibles, equipped with serrated edges, pierce the superficial layers of the epidermis, reaching the superficial dermal capillaries.
- Salivary glands release a mixture of anticoagulants, vasodilators, and anesthetic compounds. These substances prevent clot formation, dilate the blood vessels, and reduce the host’s immediate sensation of the bite.
- Blood flows into the flea’s foregut, where it is stored and later digested. The feeding episode typically lasts from a few minutes up to fifteen minutes, depending on the flea’s hunger level and the host’s response.
- After engorgement, the flea retracts its mouthparts, releases the attachment, and may move to another site or drop off the host.
The bite manifests as a small, red papule that may develop into a pruritic wheal. Repeated feeding can cause localized swelling and, in some cases, allergic reactions to flea saliva. Effective control requires eliminating the flea population on the host and in the surrounding environment, as the insect can survive for several days without a blood meal but requires a host for reproduction.