THE INSECTLIBRARY FIELD GUIDES

FleaIdentification, facts & practical guidance

Fleas are small, wingless insects in Siphonaptera. Adults jump and feed on blood, while their eggs and larvae can develop away from the animal host.

Compiled by the InsectLibrary Team · Updated 2026-09-30 · Editorial policy

Identification and lookalikes

Ctenocephalides felis - Cat Flea(c) abidanimallover, some rights reserved (CC BY). https://creativecommons.org/licenses/by/4.0/ Source: https://www.inaturalist.org/observations/404120002

Adults are flattened from side to side. Eggs are small, pale and oval; they are different from dark flea droppings. Bites alone do not establish that fleas are present. Examine pets and their resting areas for physical evidence.

Why fleas return after cleaning

The life cycle includes eggs, larvae, pupae and adults. Immature stages in carpets or bedding can sustain a problem even when adult fleas are no longer obvious on a pet.

What to do next

Vacuum resting areas and wash suitable bedding. Arrange species-appropriate treatment for every affected pet with a veterinarian. Do not put a dog product on a cat or rely on essential oils as a substitute for an appropriate treatment plan.

Flea: species profiles

Explore 33 species profiles covered by this guide, with recorded names and available photos.

Cat Flea

Ctenocephalides felis

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Dog Flea

Ctenocephalides canis

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Human Flea

Pulex irritans

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Squirrel Flea

Orchopeas howardi

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Sticktight Flea

Echidnophaga gallinacea

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Mole Flea

Hystrichopsylla talpae

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Hystrichopsylla schefferi

Sources and further reading

ipm.ucanr.edu - fleashttps://ipm.ucanr.edu/home-and-landscape/fleas/

References support the subject discussed here; they do not certify every imported directory record. Regional sources describe their own locations. Read our source and correction policy.