Wildlife Guide · Africa & Asia
Flea
Siphonaptera
The wingless parasite famous for jumping
Image: Photo: CDC/Janice Haney Carr / Wikimedia Commons (Public domain)
In brief
Fleas are tiny, wingless insects that live as parasites on the bodies of mammals and birds, feeding on their blood. They are renowned for their jumping ability, able to leap many times their own body length thanks to powerful hind legs and a spring-like protein.
By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated
Fleas are tiny, wingless insects that live as parasites on the bodies of mammals and birds, feeding on their blood. They are renowned for their jumping ability, able to leap many times their own body length thanks to powerful hind legs and a spring-like protein. Fleas can be a nuisance to pets and people and can transmit disease, and they are found nearly worldwide.
0.0025 m
Typical length
0 g
Typical weight
5 km/h
Top speed
1 yrs
Lifespan
Figures sourced from Wikipedia — Flea, Wikidata — Flea .
Flea: Quick Facts
| Scientific name | Order Siphonaptera |
|---|---|
| Diet | Hematophagous (blood of mammals and birds) |
| Habitat | On the bodies of host animals worldwide |
| Lifespan | Several weeks to a few months |
| Length | 1.5–3 mm (about 0.1 in) |
| Jump | Up to many times its body length |
| Conservation status | Varies by species |
Scientific Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Insecta |
| Order | Siphonaptera |
Conservation Status
- IUCN Status
- Least Concern (IUCN Red List category)
- Population
- Global population not compiled for this guide
- Trend
- See the IUCN Red List assessment
- Assessed
- See the IUCN Red List assessment
- CITES
- See CITES appendices
Conservation figures are drawn from the IUCN Red List and CITES; this guide links to the authoritative sources rather than restating population counts.
Key Facts: Flea
- Fleas are famous for their extraordinary jumps, able to leap distances and heights many times their own body length.
- Fleas are external parasites that feed on the blood of mammals and birds, with each species often favoring particular hosts.
- A flea's life cycle moves through egg, larva, pupa, and adult, much of it taking place off the host in bedding, carpets, or nests.
Built for jumping
Fleas are famous for their extraordinary jumps, able to leap distances and heights many times their own body length. The power comes from a rubber-like protein called resilin that stores energy and releases it like a spring. This lets a flea launch onto a passing host with explosive acceleration.
A parasitic lifestyle
Fleas are external parasites that feed on the blood of mammals and birds, with each species often favoring particular hosts. Their bodies are flattened from side to side, helping them slip easily through fur and feathers, and backward-pointing bristles make them hard to remove. Mouthparts adapted for piercing skin let them feed on blood.
Life cycle
A flea's life cycle moves through egg, larva, pupa, and adult, much of it taking place off the host in bedding, carpets, or nests. Eggs laid on a host often fall into the surrounding environment, where the larvae feed on debris before pupating. Adults emerge ready to jump onto a host and feed, sometimes after waiting for the right cue such as warmth or vibration.
Fleas and disease
Beyond the irritation of their bites, fleas can transmit diseases and parasites. Historically, certain fleas spread the bacteria responsible for plague, and fleas can also carry tapeworms and other pathogens between animals. Controlling fleas on pets and in the home helps protect both animals and people.
What WARN Does
WARN does not run a dedicated flea programme — this guide is part of the World Animal Rescue Network's free educational library. The flea is currently widespread and not globally threatened, and this guide helps readers understand the pressures that can change that. Building public understanding of species like the flea supports the broader conservation awareness that underpins WARN's partner-led rescue work across its network.
If clear, science-based wildlife guides like this help you understand and value animals, please consider supporting the World Animal Rescue Network's educational and rescue work so we can keep producing them.
Flea: Frequently Asked Questions
How far can a flea jump?
What do fleas eat?
How long do fleas live?
Can fleas spread disease?
Why are fleas so hard to get rid of?
Do fleas have wings?
Where do fleas live?
Are fleas dangerous?
How big is a flea?
Sources & References
Population figures, conservation status and biological facts on this page are drawn from authoritative scientific and intergovernmental sources.
Terms used on this page
Plain-English definitions, from our wildlife and conservation glossary.
Latest Flea Stories
Quick, fact-checked reads on the flea — amazing facts, key questions and the threats it faces.
Species
Slow Loris: Why the Internet's Favourite Pet Is a Conservation Disaster
The slow loris looks like a cartoon character — and that has nearly destroyed the species. Here is the truth behind the viral videos.
Read the storySpecies
The Snow Leopard: Why the Ghost of the Mountains Is Still Vulnerable
The snow leopard is one of the most elusive big cats on earth, with an estimated 4,000-6,500 individuals across twelve range states — including Pakistan, where WARN is preparing to operate. This briefing explains why the species was downlisted from Endangered to Vulnerable in 2017 and why that is not the success story it sounds like.
Read the storyGuides
Sun Bear vs Moon Bear: The Two Most Trafficked Asian Bears
The sun bear and the Asiatic black bear (moon bear) are the two most commonly trafficked bears in Asia — for the pet trade, for traditional medicine and for bear-bile farming. Here is how to tell them apart.
Read the storyExplore More Species
Every animal in our network faces a crisis. Learn about the others.
View all wildlife guides