Who do fleas and lice bite? - briefly
Fleas and lice consume the blood of mammals, especially humans, dogs, cats, and other warm‑blooded animals. They attach to hosts that offer appropriate skin temperature and readily accessible blood vessels.
Who do fleas and lice bite? - in detail
Fleas are obligate hematophages that obtain blood from a narrow range of vertebrate hosts. The most common species, Ctenocephalides felis (cat flea), feeds primarily on domestic cats and dogs but will also bite humans when animal hosts are unavailable. Ctenocephalides canis (dog flea) shows a similar preference for canids. Pulex irritans (human flea) displays a broader host spectrum, biting humans, livestock, and wild mammals. Bird fleas, such as Ceratophyllus gallinae, specialize in avian blood. In all cases, the insect inserts its mouthparts into the skin, releases anticoagulant saliva, and draws a small volume of blood, causing irritation and potential transmission of pathogens.
Lice are ectoparasitic insects that are largely species‑specific. Human head lice (Pediculus humanus capitis) inhabit scalp hair and feed exclusively on human blood. Body lice (Pediculus humanus corporis) reside in clothing seams and also require human blood. Pubic lice (Pthirus pubis) attach to coarse body hair of humans, including the pubic region. Animal lice are confined to their respective hosts: canine chewing lice (Trichodectes canis) infest dogs, feline chewing lice (Felicola subrostratus) affect cats, and avian chewing lice (Menacanthus stramineus) parasitize birds. Each species inserts its mandibles into the epidermis, extracts blood, and lays eggs on the host’s hair or feathers.
Key distinctions between the two groups:
- Host range: fleas may opportunistically bite multiple mammalian species; lice are generally restricted to a single host species or closely related group.
- Feeding site: fleas penetrate the skin; lice usually feed on the superficial capillaries of the scalp, body, or hair shafts.
- Mobility: adult fleas can jump several centimeters, enabling rapid host switching; lice crawl and are transferred primarily through direct contact or fomites.
Understanding these host preferences clarifies why human exposure to fleas often occurs in environments with pets or livestock, whereas lice infestations are typically spread by close personal contact within the same species.