Lawn shrimp look a bit like hopping fleas to the untrained eye, which unfairly gives them a bad name. In reality they are completely harmless, and you won’t come across them at all if you create damp areas in the garden where they can prosper without having to come out onto your lawn.
Lawn shrimp are ⅘ of an inch long, and are attracted to wet gardens when their own habitat dries out. Pale brown in color, they turn pink after death like cooked seafood shrimp. A lawn shrimp infestation isn’t serious and once your lawn is dry they’ll seek shelter in shady, moist areas again.
So let’s consider in more depth what these harmless critters are, how you got them on your lawn – and how you can get rid of them if you really need to.
How Did I Get Lawn Shrimp? (Also Called Yard Shrimp or Grass Shrimp)
These peculiar little critters occasionally appear in our yards, outbuildings or even homes. Small and harmless, but still not desirable tenants, lawn shrimp, sometimes called yard shrimp, will move into your house or garden in search of the perfect moist conditions.
Finding the right level of moisture is essential for the lawn shrimp, as they are actually a type of crustacean called the amphipod. Yes, these little guys are more closely related to crabs than bugs, and while most amphipod species live in water, the lawn shrimp prefers to dwell in damp conditions on land.
So, if you have lawn shrimp in your garden, it’s because they’re enjoying the wet topsoil. If they have scuttled indoors, it could be because outside is too dry and they’re chancing that indoors may be wetter (not generally the best idea, shrimps). Or conversely, it’s because a heavy downpour has made their outdoor habitat too waterlogged and they’re seeking moist but dryer living conditions.
They’re not a sign of uncleanliness or poor yard management: they’re simply a fact of life, especially in wetter climates. By managing the moisture levels in your yard, you can help to keep them at bay.
What Do Lawn Shrimp Look Like?
Lawn shrimp are small (the biggest they get is about ⅘ of an inch, and most are smaller than that). They start out as a pale brownish shade, turning pink after death like cooked seafood shrimp.
Because they jump about (and they’re actually known as “house hoppers” in Australia) they are sometimes mistaken for fleas. It can actually be a relief when you realise they’re shrimp not fleas, as these little critters won’t bite you. They’re related to sand fleas, those hopping bugs you sometimes see at the beach or on the dunes.
Looks-wise, they definitely resemble our edible seafood shrimp. The name amphipod comes from the Greek for “different legs”, referring to the fact that they have two kinds of legs. These are mostly short with a pair of longer ones in our shrimp’s case. They don’t have a carapace, and their bodies are rather flat.
Like seafood shrimp, they have small black eyes either side of their heads. They have two pairs of antennae, which is one of the easiest ways to identify them (if you have good eyesight).
The Lawn Shrimp Life Cycle (What Do They Eat?)
The lawn shrimp makes its home in damp dirt with good ground cover. It loves mulch, and its preferred resilience is the upper half inch of your topsoil. This keeps the critters nice and moist without them getting too wet or drying out. Like woodlice, you’ll also find them under patio pot plants, in log piles and under your trash.
This environment also provides them with their favorite food, rotting organic and animal material. One benefit of the shrimps is that they help break down this matter, helping creating richer fertilized soil.
So, in normal circumstances, the lawn shrimp will simply carry on living in your flower beds, eating decaying matter and leaving your home alone. Hatched as miniature adults, they’ll typically live for around a year in the right conditions. Because they’re not pests, can’t survive in our air-conditioned homes, and don’t bite us or our pets, they’re not a nuisance.
Problems can arise when their simple life cycle is disturbed by the wrong weather conditions. They can be flooded out of their homes, or (less commonly in damp, mulched soil) their habitat becomes too dry.
At first glance, they seem to be very high-maintenance about their living conditions. However, they have to be, due to what feels like a major design flaw in their makeup. Their exoskeleton is soft and doesn’t have a waxy coating that protects them from excessive moisture. This leaves them incredibly vulnerable to temperature variations.
Naturally, they hop off in search of a safer place to live. This is generally when we meet them.
How Serious is a Lawn Shrimp Infestation?
Basically, it isn’t. They can’t harm you, your dog or your cat, and they won’t cause any damage to your home. They are actually beneficial to your yard, being one of the animals that helps break down rotting matter and recycle it into nutritious soil.
However, none of us likes finding dead and dessicated little shrimps in our homes. They’re more of a temporary nuisance than anything else. Once they enter your home (and this isn’t something they normally do: it’s their extreme-weather plan), the amphipods tend to die very quickly as they dry out. You’re unlikely to have to deal with any live ones.
But, they can cause a few issues if their habitats start to dry out. Should their supply of mulch or dead leaves dry up, the resident lawn shrimp will search out the nearest wet place. If you have a swimming pool, ornamental pond or even a fish tank, this is where they’ll head.
They make for darker areas of your pool such as the filters. Yes, you’ve guessed it. A lawn shrimp infestation can clog up your swimming pool or pond filter, which is potentially damaging. If you own a swimming pool, you definitely do not want an infestation, especially if the whole family moves in…
How Do I Get Rid of Shrimp in My Lawn?
Because lawn shrimp can’t survive in dry conditions, the simple answer is to take away their damp habitats. Removing ground cover and keeping on top of piles of leaves can prevent an infestation from ever occurring. Cut down on mulching, rake your beds regularly, and don’t overwater your flowers.
There’s rarely a need for chemical treatment for lawn shrimp removal, simply because they are so vulnerable to habitat. Change their environment, and they simply can’t survive. Provided they are not causing you any problems, you might even want to just let them carry on living in your yard, breaking down that organic matter.
Adopting a “live-and-let-live” approach can also mean that they’re less likely to enter your home, shed or swimming pool. They’ll simply stay in that damp half inch of topsoil.
If you have a pool in your yard, you’re less likely to be as chilled about lawn shrimp, as they can actually cause damage and disruption. You can call in pest control for advice; however as chemical treatments and pesticides aren’t recommended for amphipods (they’re not technically pests), they’ll probably simply tell you to dry out their habitats.
The easiest way to prevent ever having a lawn shrimp invade your territory is to make it unwelcoming. Try not to have shady, damp areas of soil by removing ground cover and regularly raking the topsoil. Lift up plant pots, trash cans and other static objects in your yard so that they can’t settle under them.
You can prevent them coming inside by having good seals around your doors. Their flat bodies can squeeze under gaps, so if you eliminate the gap, you remove their entry points. And if they do get it, don’t worry. They can’t settle in the dry environment or your house or garage, so you won’t get an infestation inside.
Lawn Shrimp FAQ
How Do Lawn Shrimp Get in the House?
The most common way for lawn shrimp to get in the house is under the front or back door.
Lawn shrimp live very precarious lives. Not only do they have a short list of predators, like birds, but their exoskeleton leaves them vulnerable to changes in the weather. If their environment gets either too wet or too dry, they have to relocate – and fast.
Ideally, lawn shrimp try to live close to their favorite meal, wet leaves. They love moist compost in dim spots, like under trees, bushes and in flower beds. They can happily live in the topmost inch of your lawn.
But after several days of hard rain or a dry spell, your lawn shrimp may be forced to relocate. Most often they will be found on sidewalks, raised patio slabs or just inside your garage, trying to avoid drowning or death by desiccation.
Sometimes you may find them inside your house. The gap between the bottom of your front or back door and the jamb is a good entry point for them. To keep them out, consider installing a door sweep to lessen the gap.
Jumping lawn shrimp are indicators that your lawn is either too wet or dry. You may not be able to address the too dry problem due to watering restrictions. But if the problem is that your lawn is too wet, you may be able to fix the problem.
Pay close attention to the amount of watering you do, because you may be watering too much. Rain gauges or an automatic sensor on your sprinkler system can help. If your lawn has areas that turn into small lakes, think about a French drain to help move out the water. Overturn soggy, mulched garden beds.
Are Shrimp in My Yard Harmful?
Nope. In fact, even though the whole idea of lawn shrimp may disgust you – and seeing them jump around is frankly creepy – they are good for your yard.
Lawn shrimp are at the bottom of your yard’s food chain, which is an important spot. Lawn shrimp are scavengers or detritivores. They devour decomposing leaves, rotting mulch, leaf mold, roots, and flowers, then poop out nutrients into the soil.
Surprisingly, most exterminating companies recommend that you not use poison. Because they are at the bottom of nature’s food pyramid, they can, in turn, poison many other creatures. Also, since they have a scant 24 hours to react to changes in their environment, many will simply perish.
If you notice a bunch of dead lawn shrimp on a sidewalk or in your garage, simply use a shop vac to get rid of the carcasses or you can add them to your compost pile.
Where Do Lawn Shrimps Come From?
We in the US can blame – or thank – the Aussies for lawn shrimps. Amphipods were first described in New South Wales, Australia. They were first described in the US in California in 1918, purportedly arriving on a eucalyptus tree.
Today, there are around 90 species in the US and Canada. Most live in freshwater or saltwater, but some are terrestrial, like lawn shrimps and beach fleas.
How Long Do Grass Shrimp Live?
In ideal conditions, a lawn shrimp can live a year. Unlike their aquatic cousins, lawn shrimp have no carapace, which is the hard covering over their exoskeleton. So, when the rains come, they can drown if your lawn gets too soggy. Conversely, if your lawn gets too dry, they will desiccate.
When their environment gets inhospitable, they will start frantically jumping around, searching for a way to survive. If they don’t find another moist home, they will die within 24 hours.
What Are the Tiny Bugs That Look Like Lawn Shrimp?
You may be looking at a silverfish. Silverfish are insects that look like shrimp or crustaceans. They are tiny, nocturnal bugs that prefer warm and moist environments. They love to feed on several household items like paper, glue, cereal, linens, books, wallpaper and carpet.
Do Lawn Prawns Bite?
Nope. Although they do have chewing mouthparts, they can’t bite you.
Can You Eat Grass Shrimp?
Yup. We found one wild food aficionado who par boiled them, dipped them in egg and flour, and then fried them up. They said the taste was only mildly shrimpy but the crunch was spectacular.
That’s not for me though thanks! 🙂
Are Ghost Shrimp and Grass Shrimp the Same?
Nope, but they are relatives. Ghost shrimp, also known as glass shrimp, are decapods. Lawn prawns (aka grass shrimp or lawn shrimp) are amphipods. While they are both members of the order of crustaceans, ghost shrimp have five pairs of legs – decapod means 10 legs – while lawn shrimp have eight pairs.
The Greek prefix amphi means both kinds or different, while poda is feet. Amphipods have two different types of feet – some for walking and some for swimming. Grass shrimp have five sets of legs for walking (or jumping) and three for swimming.
Amphipods are a very diverse group – there are over 10,000 species worldwide. Around 8,000 species are marine and the rest are freshwater or terrestrial. The largest marine amphipod is around 11 inches long and the smallest is around 0.04 inches long (1 millimeter).
Amphipods have been found at oceanic depths of up to 17,400 feet. Famously, Russia’s Lake Baikal has over 350 different amphipod species.
How Fast Do Grass Shrimp Reproduce?
Once eggs are deposited on the underside of a female’s body, they typically hatch within one to three weeks. Most terrestrial species only manage to have one brood in their lifespan.
One freshwater amphipod can have up to a whopping 15 broods in their lifespan, which is 15 months. These common amphipods, Hyalella azteca, are used as environmental indicators in lakes, ponds, and streams.
Can Grass Shrimp Live in Freshwater?
Lawn or grass shrimps are terrestrial, but they have plenty of relatives who are aquatic, in both freshwater and saltwater. Grass shrimp and beach fleas (aka sand hoppers or sand fleas) are both terrestrial amphipods, although they still need moist environments.
Are Lawn Shrimp Harmful to Dogs?
No, they won’t harm your dogs, cats or even your kids – even if they are ingested.
As mentioned above, lawn shrimp are completely harmless and have only come out onto your lawn seeking moisture, due to a prolonged period of hotter weather drying out their preferred shady, moist areas of the garden.
There’s no need to take action to get rid of them, as once your lawn has dried again they’ll seek out those damp locations once more – such as flower beds, leaf piles and compost heaps. So they’re probably in your garden all the time, you just don’t normally see them.
In fact, the only way to completely get rid of them is to make all areas of your garden damp-free so they go somewhere else completely – which is not possible or necessary even in wet areas.
The only thing to worry about with lawn shrimp is your swimming pool if you have one – as the little critters can clog up your filter, but otherwise there’s no need to worry. They’ll soon find their way off your lawn and back home again.
Homeowner and property investor Larry Jones founded Take a Yard in 2020 to bring you the very best outdoor living content, based on his years of experience managing outside spaces. Read more >