How do fleas bite cats and humans? - briefly
Fleas use needle‑like stylets to pierce the epidermis, delivering saliva that contains anticoagulants and irritants, which provokes itching and inflammation. The insects attach to a host’s fur or clothing and bite repeatedly, feeding on blood from both felines and humans until fully engorged.
How do fleas bite cats and humans? - in detail
Fleas possess specialized mouthparts known as stylets, which consist of a pair of slender, needle‑like incisors and a pair of serrated maxillae. The incisors penetrate the host’s epidermis, while the maxillae scrape tissue to create a blood pool. Salivary secretions containing anticoagulants and anesthetic compounds are injected simultaneously, preventing clotting and reducing the host’s perception of the bite.
When a flea attaches to a cat, it typically selects a region with thin skin and abundant blood flow, such as the neck, base of the tail, or abdomen. The feeding cycle proceeds as follows:
- The flea lands and quickly anchors with its hind legs.
- Stylet insertion occurs within seconds, reaching the dermal capillary network.
- Saliva is released, maintaining fluid flow.
- Blood is drawn up through the pharyngeal pump and stored in the flea’s midgut.
- After engorgement, the flea disengages and may move to another site to repeat the process.
In humans, the bite pattern is similar but often occurs on exposed areas like the ankles, calves, or lower back. Differences include:
- Fleas may be less likely to remain attached for prolonged periods because human grooming and clothing disturb them.
- Human skin is generally thicker than feline skin, requiring slightly deeper stylet penetration.
- The host’s immune response can be more pronounced, leading to localized erythema, papules, or intense itching.
Salivary components trigger hypersensitivity reactions in both cats and people. Repeated exposure can cause sensitization, resulting in larger wheals and secondary bacterial infection from scratching. Fleas also serve as vectors for pathogens such as Bartonella henselae (cat‑scratch disease) and Rickettsia spp., which are transmitted when the flea regurgitates infected material during feeding.
Effective control relies on interrupting the feeding cycle: regular use of ectoparasitic agents, environmental decontamination, and prompt removal of fleas from the host’s coat or skin.