What do fleas feed on? - briefly
Fleas are obligate blood‑sucking parasites that obtain nutrition by piercing the skin of warm‑blooded hosts such as dogs, cats, rodents, and humans. They ingest only small volumes of plasma and red blood cells during each feeding.
What do fleas feed on? - in detail
Fleas obtain nourishment primarily through hematophagy, drawing liquid blood from vertebrate hosts. Adult specimens attach to mammals, birds, or occasionally reptiles, inserting a serrated proboscis into the skin to access capillaries. Salivary enzymes prevent clotting, allowing continuous ingestion of plasma and erythrocytes. A single feeding event may deliver 0.5–1 µL of blood, sufficient to sustain the adult for several days; however, females require multiple meals to produce a full egg batch.
Feeding behavior varies among life stages:
- Adults: exclusive blood consumers; require at least one meal to initiate oviposition, subsequent meals support egg development and survival.
- Larvae: do not feed on host blood; instead, they consume organic matter such as adult flea feces (rich in partially digested blood), desiccated skin cells, and environmental debris. This diet supplies proteins and lipids necessary for pupation.
Host selection is driven by temperature, carbon‑dioxide emission, and movement cues. Warm‑blooded animals provide optimal conditions, with dogs, cats, and rodents representing typical targets. Birds host specialized flea species adapted to feathered integuments. Reptilian hosts are less common and usually support flea taxa that have evolved tolerance to lower body temperatures.
Feeding frequency is influenced by environmental temperature and host availability. In temperate climates, adults may feed every 2–3 days, whereas in warmer settings, intervals shorten to 12–24 hours. The volume of blood ingested correlates with the flea’s size; larger species such as Ctenocephalides felis consume more per meal than smaller genera.
Saliva contains anticoagulants, vasodilators, and immunomodulatory compounds that facilitate blood flow and reduce host inflammatory responses. These substances are responsible for the characteristic itching and dermatitis associated with infestations.
In summary, adult fleas rely solely on vertebrate blood, while immature stages subsist on organic residues derived from adult excreta. Host preference, feeding intervals, and blood volume are modulated by species‑specific adaptations and ambient conditions.