Lawn shrimp, also known as terrestrial amphipods, are small crustaceans found in moist environments. They thrive on the surface or within the top half-inch of mulch and damp soil, particularly after rains when they may migrate into garages or under the doors of houses source.
These creatures are often present in leaf mold beneath shrubbery and can be found in soft ground up to a depth of 13mm. Although they can be a nuisance when invading homes, lawn shrimp are harmless and typically feed on decaying plant matter, contributing to the natural decomposition process in gardens and landscapes. So, understanding their habits can help in managing their presence in outdoor spaces.
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Understanding Lawn Shrimp
Amphipod Basics
Lawn shrimp, scientifically known as Arcitalitrus sylvaticus, belong to the Amphipoda order within the Crustacea class. These crustaceans are close relatives of other amphipods like sand fleas and beach hoppers.
Distinctive Features
- Color: Lawn shrimp have a reddish-brown color, which helps them camouflage in natural environments like soil and leaf litter.
- Antennae: They possess two pairs of antennae, which function as sensory organs for detecting their surroundings.
- Size: Lawn shrimp typically measure up to 15-20 mm in length, making them relatively small creatures.
Habitat and Distribution
Lawn shrimp are terrestrial amphipods, meaning they live on land rather than in water. Their preferred habitats include damp and decaying vegetation, such as leaf litter or compost piles. Commonly found in Australia, they have also been introduced to other regions globally.
| Habitat | Location |
|---|---|
| Damp vegetation | Australia |
| Decaying leaf litter | North America |
| Compost piles | Europe |
Although lawn shrimp are harmless to humans, they can sometimes become pests when they invade yards, gardens, and homes. To control their population, simple measures such as reducing moisture and removing decaying vegetation can be effective.
Life and Behavior
Feeding Patterns
Lawn Shrimp, also known as yard shrimp or grass shrimp, primarily feed on organic matter. They are known to consume:
- Decomposing leaves
- Algae
- Invertebrate organisms
- Insects
Their feeding habits contribute to the recycling of nutrients in their moist habitats.
Moisture Dependence
Lawn Shrimp are highly dependent on moisture to survive. They can be found in various moist areas, such as:
- Wet topsoil
- Freshwater lakes and ponds
- Moist soil beneath plants
After heavy rains, they may migrate into garages or under doors of houses in search of moisture. As moisture-dependent creatures, their presence can be reduced by maintaining drier surroundings.
Life Cycle
The life cycle of Lawn Shrimp includes several stages:
- Eggs are laid in moist soil or freshwater habitats
- Nymphs emerge, which closely resemble the adult form but are smaller and pale brown in color
- The nymphs molt and grow, eventually developing into adult Lawn Shrimp
Adult Lawn Shrimp are characterized by their black eyes and preference for wetter climates. They are an important part of the ecosystem as they help break down organic matter and recycle nutrients back into the environment.
Lawn Shrimp and Your Garden
Impact on Plants
Lawn shrimp, also known as terrestrial amphipods, generally have a minimal impact on plants. They feed on decaying plant matter, such as dead leaves and grass, which are often found on the soil’s surface. Their feeding habits are mostly harmless to living plants, but in rare cases, they can cause minor damage if an infestation is severe.
Role in Soil and Mulching
These small crustaceans play a role in breaking down organic matter. They live on the top layer of soil and mulch, up to a depth of 13 mm, where they help decompose plant matter and contribute to the soil’s nutrient cycle. Due to their activity, they can actually improve the quality and fertility of your garden’s soil and mulch.
Beneficial Aspects
- Break down dead plant material
- Improve soil fertility
- Attract birds and other beneficial insects
Lawn shrimp are not usually considered pests, but can become a nuisance for homeowners if they invade garages or homes following heavy rains. They are mainly found in humid regions, such as Florida and California. However, these tiny critters are harmless to humans and pets and do not bite or sting. Thoroughly maintaining your garden, such as removing excess mulch and keeping a tidy landscape, can help prevent lawn shrimp infestations.
Controlling Lawn Shrimp Infestations
Preventive Measures
Lawn shrimps thrive in moist conditions, and typically live on the surface of mulch and moist ground up to a depth of 13 mm. By controlling the moisture level in your yard, you can prevent infestations. Here are a few tips:
- Avoid overwatering: Reducing the frequency of watering can lower the chances of attracting lawn shrimps.
- Well-drained soil: Ensure your garden has proper drainage systems to prevent waterlogging.
- Shady areas: Reduce shady spots in your garden by trimming overgrown plants or removing unnecessary objects.
Natural Predators
Birds are known natural predators of lawn shrimps and other tiny creatures, including worms and insects. Attracting birds to your garden can help naturally control infestations:
- Set up bird feeders
- Establish nesting spots or birdhouses
- Plant bird-friendly flora
Safe and Effective Pest Control
If you are dealing with a lawn shrimp infestation, it is necessary to employ safe and effective pest control methods. Consider the following options:
- Manual removal: Collect lawn shrimps with a vacuum or by hand, and dispose them far from your property.
- Baits: Place meat baits near infested areas to attract and trap lawn shrimps.
- Insecticides: Select environmentally safe insecticides, preferably with a short residual time to limit ecosystem disruption.
| Method | Pros | Cons |
|---|---|---|
| Manual removal | Non-toxic, no harm to the ecosystem | Time-consuming, labor-intensive |
| Baits | Targeted control, less risk to plants | May attract other pests |
| Insecticides | Effective in killing lawn shrimps | Potential harm to non-target organisms, ecosystem disruption |
25 Comments.
Thank you so much for this information. We’re in Warrandyte, Victoria, and are plagued by these for the first time in 30 years. Every morning we have thousands dead on our tiled floor. Have tried Mortein bombs but to no avail. I guess we just have to keep vacuuming them up each day until the long summer sets in and they go away. Had spent a while trying to find out what these were and finally found your site and great explanation and pictures. Many thanks.
We would not recommend any pesticides. They will not harm your home.
My friends and I
Took a night walk at his parents beach house at the Potomac River delta to the Chesapeake Bay in Heathesville Va. While walking we saw… Hundreds of these things. None of us had any clue what they were. I google searched what I called, “land shrimp” because they had antennaes and tails that would flip like shrimp but crawled like waterbugs or silverfish, quckly I might add. They were very moist and almost slimy. Are these things truly land shrimps?
My friends and I
Took a night walk at his parents beach house at the Potomac River delta to the Chesapeake Bay in Heathesville Va. While walking we saw… Hundreds of these things. None of us had any clue what they were. I google searched what I called, “land shrimp” because they had antennaes and tails that would flip like shrimp but crawled like waterbugs or silverfish, quckly I might add. They were very moist and almost slimy. Are these things truly land shrimps?
I found Lawn Shrimp in my pool after a hard rain. There is a palm tree over this area where they were found— in Belize Central America.
Thanks for that information. We now know what they are!
We are finding quite a few dead ones each morning around two sliding doors to outside.
My husband wants to know, do you think it would be beneficial to spread a layer of lime on the concrete outside of the sliding doors? We have no pets and no children (left the nest)!
Many thanks.
Thanks for that information. We now know what they are!
We are finding quite a few dead ones each morning around two sliding doors to outside.
My husband wants to know, do you think it would be beneficial to spread a layer of lime on the concrete outside of the sliding doors? We have no pets and no children (left the nest)!
Many thanks.
We don’t understand why you want to use the lime. Many gardeners use lime. According to Backyard Gardener: “The main reason for using lime is to reduce the acidity of a soil that is acid or, in other words, to sweeten the soil. Few plants will grow well in a very acid soil mainly because their intake of plant foods is reduced; phosphates, in particular, get ‘locked up’ in acid soils. There is often a shortage of calcium in very acid soils.”
ps should have added to above post that we are in Currumbin on the Gold Coast.
I’ve just found a load of these! I’m on the Isle of Arran, west coast of Scotland, and yes, we’ve had a lot of very wet weather. Not got the best eyesight nowadays, and my carpet is the same colour, which is maybe why I’ve not noticed them before, but I found 6! Have now vacuumed very thoroughly and will pay more attention in future!
Thank you so much for this explanation. I have been finding these in one room in the house right near the back door. I have never seen these before and I am so happy to finally know what they are and that there is no need for concern, except for a mess on the floor every morning.
It may be of interest to you to know that we found a couple of dozen of these little critters on our bedroom floor in Berry South Coast of N S W for the first time this week. We have had a LOT of rain over the last few of weeks.
I live in Hampstead NC and noticed these lawn shrimp in my cats water dish.
Had these many years ago in the 80s . Never saw them again. I live in São Paulo Brazil. They invaded the slated floor after a period of heavy summer rain. Cheers!
Caswell Beach, NC. My carport is evenly dusted with these dead bodies daily. Thanks so much for solving the mystery.
Thank you so much for this information. Have been finding these weird little bugs all over the dining room floor near the back door on & off over the last few months. Had spent quite a while trying to find out what these were and finally found your site and great explanation and pictures. We live in western Sydney where we haven’t had that much rain but had been watering more due to the extra hot weather. Many thanks.
We are happy to hear we were helpful.
I have a bunch of dead bugs in my car port that look like lawn shrimp…we’ve had lots of rain day and night in Maui…the house is raised so hopefully if there are more won’t get in the house. I have palm trees…I’be been here 9 months and never saw before
I’ve found what appears to be the same thing on my dining tiled floor in Glenwood, Western Sydney. All have been dead.
We live in Werribee, Melbourne and just found a little colony of them under the compost. At first we thought they were fleas (as they do jump) but on closer examination found them different and larger. Appears we have created a perfect living environment for these little guys. We did not spray them as they were doing no harm.
We live in Byron Bay in Lilli Pilli a beautiful rainforest area and have had a fairly consistently wet winter.. perhaps some recent downpours have caused them to come in though we’ve never had them in the 3 previous years living here, I guess the conditions must be just enough for them to escape the rain. We have recently mulched the compost outside our sliding doors which have an additional sliding bug screen door, but they must be slipping under it poor little guys.. they can’t win 😐 thanks for all your info I’m so glad I figured out what and why they were in here. I googled ‘bug that looks like a prawn’ and lawn shrimp showed up ! so funny. Didn’t know they hopped but I saved one the first night hehe, was a bit dumbfounded when more showed up.
Thank you, very informative. We live on Central Coast and have found them in our swimming pool. I thought they were white but realised must be the chemicals bleaching them. Found a few near back door and they are definitely orange. Hoping they will go away.
Please do not use the British Isles or refer to Ireland as being part of the British isles. This is disrespectful and no longer acceptable. If you must refer to both countries, you can use Ireland and the Uk, but remember Ireland is independent please and be thoughtful and respectful.
I had been trying to find out what these little critters were. And then I found your website. Thank you. I am in Brisbane QLD Australia and we have had a very wet winter following a wet summer and going into another wet period. I guess they are going to be around for a bit!
Do the lawn shrimps do any harm? eg: to plants?