# Human flea (Pulex irritans) > A small, wingless blood-feeding flea that infests humans and many mammals and can bite, cause itching and transmit disease under certain conditions. Source: https://insectscanner.com/species/human-flea/ (updated 2026-10-10) ## Is it dangerous? **Biting pest.** Pulex irritans bites cause itchy, irritating welts and can trigger allergic dermatitis in sensitive people. Flea bites can become secondarily infected from scratching. P. irritans has been associated with transmission of some bacterial pathogens in historical outbreaks, but it is not a primary vector like some rodent-associated fleas. If you have many bites, severe allergic reactions, spreading redness, fever or signs of infection, seek medical advice. Clean bites with soap and water, apply an antiseptic and use topical anti-itch treatments or oral antihistamines as directed. **Pets:** Fleas feed on pets and can cause itching, hair loss, flea allergy dermatitis, anaemia in heavy infestations, and can transmit tapeworms (Dipylidium caninum) if pets ingest infected fleas. Treat pets with veterinarian-recommended flea control products and consult a vet for heavy infestations or sick animals. ## Quick facts - Scientific name: Pulex irritans - Order: Siphonaptera (Fleas) - Family: Pulicidae (Fleas) - Size: 1.5-3.0 mm long - Colours: Dark brown, Blackish brown - Habitat: Human dwellings, animal resting areas, nests and burrows; larvae develop in carpets, bedding, cracks in floors, soil and detritus near hosts - Range: Cosmopolitan; recorded worldwide in association with humans and a variety of mammals - Active: Active year-round in heated buildings; outdoors most active in warm months; adults bite any time of day but often feed when hosts are resting - Lifespan: Adults live weeks to a few months depending on temperature, humidity and availability of a host - Effect on plants: Harmless - Pest: yes ## Overview Pulex irritans, the human flea, is a wingless, laterally compressed biting insect in the flea family Pulicidae. Adults feed exclusively on blood and will bite people, pets and wild mammals. The species is adapted to living close to hosts and in human dwellings, animal nests and resting sites. While not as important as some other flea species in disease transmission, P. irritans can cause itchy bites, allergic dermatitis and has been implicated in carrying bacterial pathogens in certain circumstances. Human fleas complete a complete metamorphosis with egg, larva, pupa and adult stages. Non-adult stages develop off the host in carpets, bedding, cracks, soil and animal nests where they feed on organic debris and adult flea feces (dried blood). Control focuses on treating pets and the environment because adults spend most of their time on hosts or in nearby resting sites. ## How to identify it Adults are small (about 1.5-3.0 mm), flattened sideways, wingless and jump strongly. They are dark brown to black, shiny, and have long legs adapted for jumping. Pulex irritans lacks the genal and pronotal combs (rows of spines) that are present on some other common fleas (for example the cat flea Ctenocephalides felis). The head is relatively short and the body is covered in backward-directed bristles that help it move through hair or fibers. - Small (1.5-3.0 mm), wingless and laterally flattened insect that jumps strongly - Dark brown to black and shiny with backward-directed bristles - Lacks genal and pronotal combs (rows of spines) that are present on cat and dog fleas (Ctenocephalides spp.) - Short head compared with some other flea genera ## Lookalikes - **Cat flea** (Ctenocephalides felis): Cat fleas usually have genal and pronotal combs (rows of spines) visible on the head and thorax; C. felis is also very common on pets whereas P. irritans lacks these combs. - **Dog flea** (Ctenocephalides canis): Similar to cat flea but generally has different comb spine arrangement; both Ctenocephalides species possess pronotal and genal combs unlike Pulex irritans. - **Pulex simulans (a close relative)** (Pulex simulans): Distinguished from P. irritans by specialist morphological characters requiring microscopic examination; non-experts usually rely on host and region plus expert ID. ## Life cycle - **Egg:** Tiny white eggs laid on the host or in the environment; they fall into bedding, carpets and crevices where they hatch in days to weeks depending on conditions. - **Larva:** Wormlike, blind larvae feed on organic debris and adult flea feces (dried blood) in the environment; development takes 1-3 weeks or longer in cool conditions. - **Pupa:** Larvae spin cocoons and pupate; the protected pupa can remain dormant for weeks to months and emerge when vibrations, carbon dioxide or warmth signal a host is near. - **Adult:** Wingless, jumping adults seek a blood meal and usually live on a host or nearby resting sites; females begin laying eggs after a blood meal. ## Diet and predators - Young eat: Organic debris, skin flakes, and adult flea feces (dried blood) found in the environment - Adults eat: Blood of mammals (humans, dogs, cats, livestock and wild mammals) - Predators of the young: Predatory mites, ants, some beetles, and microbial pathogens in the soil or debris - Predators of adults: Spiders, ants, some predatory beetles, and birds when dislodged from hosts ## Effect on plants and gardens Does not feed on or damage plants; no direct impact on gardens ### How to get rid of it Find and treat the source: fleas usually come from pets, livestock or wildlife (for example nests in attics or under floors). Treat all pets with veterinarian-recommended flea products. Wash bedding and pet bedding in hot water, vacuum carpets, upholstery and floor cracks thoroughly and repeatedly (emptying the vacuum outdoors), and use a product containing an insect growth regulator (IGR) labelled for indoor flea control, following the label. Remove or block access to wildlife nests near the home. For persistent or heavy infestations, contact a licensed pest professional. ## Where and when to find it Adults: on hosts (people, pets) and in resting sites such as bedding and pet beds. Eggs, larvae and pupae: carpets, upholstery, cracks in floors, soil near animal bedding and nests. - Best time: Year-round indoors; outdoors mainly in warm months. Observe bites or flea activity at night or when hosts are resting. - Tips: To detect fleas, comb pets over white paper or a light-colored cloth to see jumping black dots. Use a fine-tooth flea comb on animals and inspect pet bedding and carpet near sleeping areas. ## Fun facts - Unlike many insects, fleas are wingless but are excellent jumpers thanks to strong hind legs and elastic proteins in their bodies. - Pulex irritans is flexible in host choice and will feed on humans, domestic animals and wildlife. - Flea pupae can stay dormant in cocoons for months and emerge when they detect a nearby host (vibrations, heat, carbon dioxide). ## Frequently asked questions ### Do human fleas bite? Yes. Adult Pulex irritans feed on blood and their bites cause itchy welts on people and animals. ### Are human fleas dangerous? They are a biting nuisance and can cause allergic reactions and secondary skin infections. They have been associated with bacterial disease transmission historically, but they are not a primary vector today in most regions. ### Why do I find fleas in my house? Fleas are often brought into homes on pets or wildlife. Eggs and larvae develop in carpets, bedding, cracks and pet resting areas, leading to ongoing indoor infestations if not treated. ### How do I get rid of human fleas? Treat pets with veterinarian-recommended flea products, wash bedding and vacuum carpets and furniture thoroughly (dispose of vacuum bag or empty canister). Clean and treat pet sleeping areas, use insect growth regulators (IGRs) and consider professional pest control for heavy infestations. ### Can fleas transmit plague? Some flea species can transmit Yersinia pestis (plague). Pulex irritans has been implicated in some historical outbreaks but is generally a less efficient plague vector than rodent-associated fleas; plague transmission is rare today and depends on local disease ecology. ### Will flea bites go away on their own? Mild flea bites usually resolve in a few days to a week. Keep bites clean, avoid scratching, and use topical anti-itch remedies or oral antihistamines if needed. See a doctor for severe reactions, signs of infection or persistent symptoms. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/308321), [Wikipedia](https://en.wikipedia.org/wiki/Human_flea). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.