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.
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.