Flea
Siphonaptera
Quick answer
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.
Flea facts at a glance
| 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 |
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Insecta |
| Order | Siphonaptera |
Where it lives
On the bodies of mammals and birds worldwide; wingless parasites famous for their jumping.
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.
Frequently asked questions about the Flea
How far can a flea jump?
Fleas can leap many times their own body length, an extraordinary feat for their size. The jump is powered by a spring-like protein called resilin that releases stored energy in an instant.
What do fleas eat?
Fleas are parasites that feed on the blood of mammals and birds. Different species tend to favor particular hosts, such as cats, dogs, or rodents.
How long do fleas live?
Adult fleas typically live several weeks to a few months when they have a host to feed on. Much of the life cycle, including the egg, larva, and pupa stages, takes place off the host.
Can fleas spread disease?
Yes. Fleas can transmit diseases and parasites, and historically certain fleas spread the bacteria that cause plague. They can also carry tapeworms between animals, which is why flea control matters.
Why are fleas so hard to get rid of?
Much of the flea population lives off the host as eggs, larvae, and pupae in bedding and carpets, so treating only the animal misses many fleas. Effective control treats both the pet and its environment.
Do fleas have wings?
No. Fleas are wingless insects. Instead of flying they rely on their powerful hind legs to jump onto hosts and move between them.
