Sand Fleas in California

Written by Nixza Gonzalez
Updated: November 23, 2022
Share on:


California is a large state that is home to about 300 species of mammals, 600 types of birds, and 765 insects. Many animals are referred to as sand fleas, despite not being fleas at all, ad depending on the specific type of animal referred to, sand fleas can be classified as either insects or crustaceans.

Keep reading to learn more about the animals called sand fleas in California!

Types of Sand Fleas in California

There are many common animals referred to as sand fleas, that aren’t aren’t related. For example, California beach fleas, mole crabs, and Megalorchestia californiana, are unique animals with few similarities beyond the name that they share: sand flea. Let’s learn more about these three distinct animals!

California Beach Fleas

Tunga penetrans, or California beach fleas, are actually fleas! These tiny sand fleas feast on blood by burrowing underneath the first layer of skin. A common nickname for them is the chigoe flea. Seldom larger than 1 millimeter (.03 inch), they are difficult to see. They are extremely common in California deserts, beaches, and all over L.A. While they usually live and breed in wet and sandy areas, you can accidentally transport them to your home, leading to an infestation. They are native to Central and South America. These nasty pests can cause tungiasis when the female beach flea burrows into the skin of its host, laying her eggs. She dies shortly after, rotting away, still stuck beneath the host’s skin. If left untreated, tungiasis can develop into gangrene.

 Tunga penetrans, or California beach flea on a natural piece of wood next to the eye of a silver metal sewing for a size comparison. The beach flea looks lie a white pearl with a small brown triangle in its center at the top.

Seldom larger than 1 millimeter (.03 inch) California beach fleas are difficult to see.

© – License

Mole Crabs

Mole crabs , Emerita analoga, are nothing like California beach fleas. They are small crustaceans that look like large fleas to some people. However, they are small crabs, rarely growing larger than 3.5 centimeters (1.5 inches). Mole crabs are also known as sand crabs. You can find these small sea animals from Northern California all the way down the coast to Mexico. Their shells are thick and egg-shaped with white, cream, yellow, and sometimes purple markings. The female mole crab is larger than male mole crab, to aid the carrying of her brightly colored eggs. These crustaceans are common along the surf and burrow deeply into the sand in large groups. They also blend into the sand, which is a defense against predators. Anglers hunt for mole crabs to use as bait since shallow swimming fish like pompanos and red drums eat them regularly.

A grenish/grayish mole crab on a tan colored sandy beach.

Anglers hunt for mole crabs to use as bait since shallow swimming fish like pompanos and red drums eat them regularly.


Megalorchestia Californiana

California beach fleas, Megalorchestia californiana, are often mistaken for mole crabs, but they are different. Megalorchestia californiana are one of the most common species of sand-hoppers in California. These small sand hoppers, also known as the long-horned beach hopper, live on slightly sloping sandy beaches or higher up on flater beaches, away from the threat of surf. They live in large groups in burrows or under dead seaweed. At night, they come out of their hiding spaces and feast on dead organic matter including items left by beachgoers. Megalorchestia californiana grows up to 2.5 centimeters (1 inch) long with antennae that are sometimes longer than their bodies. They are orange and white, sometimes blending into the sand.

A portrait of a long-horned beach hopper against the sand. It looks rather like a tiny shrimp or krill with a transparent body and two red-orange antennae protruding from the front of its head.

California beach fleas are often mistaken for mole crabs.

© – License

What beaches have sand fleas in California?

Many beaches have sand fleas in California, especially those in Orange county. Mole crabs are a lot more common than the biting sand flea. You can find mole crabs along the surf, but it may require some digging. However, a few beaches in California have seen a lot of biting sand fleas, including beaches in and around San Diego. When seaweed washes onto shore and is not disposed of quickly, it quickly becomes a breeding ground for Tunga penetrans, the California sand flea, whose bite can be problematic. Seaweed washing ashore is a regular occurrence on San Diego’s Pacific Beach, causing sand flea infestations.

A close up of a tunga penetrans that was removed from beneath a person's skin. It's rather bloody. On some sort of surgical blue background.

The California sand flea’s bite can be problematic.

© – License

Can sand fleas infest your home?

Mole crabs and the Megalorchestia californiana are unlikely to infest your home. However, biting California beach fleas can hitch a ride from the beach into your family’s home. They are small, white,and can live in many conditions. Beach fleas hide in carpets, rugs, and other thick fabrics Chigoe fleas are not very common in California since they thrive in tropical and sub-tropical climates. However, infestations do happen. If you suspect you have an infestation in your home, call a California pest exterminator.

Up Next:

The photo featured at the top of this post is ©


  1., Available here:
  2., Available here:
Share on:
About the Author

Nixza Gonzalez is a writer at A-Z Animals primarily covering topics like travel, geography, plants, and marine animals. She has over six years of experience as a content writer and holds an Associate of Arts Degree. A resident of Florida, Nixza loves spending time outdoors exploring state parks and tending to her container garden.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.