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.
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 |
Reader Emails
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Lawn Shrimp in Australia
small bug infestation
Location: Brisbane, Queensland, Australia
January 18, 2011 8:55 pm
Over the last 2 months, we’v e been finding these little critters dead on our floors. Looks like they’re getting in via cracks under door, or through flyscreens, etc.
We’ve never seen a living one – they’re always dead (we get the house sprayed every year) – but we can find up to a hundred dead on the floor every few days. (more close to a door, thinning out futher into a room). They are up to a centimetre in length. What are they ??
Hope you can shed some light.
Cheers,
Andrew.
Signature: Curious.
Dear Andrew,
These are known Lawn Shrimp or Househoppers, Arcitalitrus sylvaticus, a terrestrial Amphipod that is native to Australia. They are not usually noticed until they enter homes in large numbers and promptly die. According to BugGuide, the natural habitat is: “Moist soil and organic matter within 13 mm of the surface, often among ivy or other ground covers, mostly eucalyptus. Their exoskelton has no waxy coating to keep moisture in, so they can’t survive dryness. They drown in water, though, so they need continuously moist, but not waterlogged conditions.” The torrential rains and flooding in Australia we are reading about is causing the Lawn Shrimp to flee the landscaping around your home. They are just coming in out of the rain. BugGuide explains: “These are rarely seen except when flooding or lack of moisture forces them to abandon their home in the soil in search for suitable conditions. At such times they often end up dieing on pavement or in homes and become a nuisance. Once they start appearing, there’s not much that can be done except to sweep them up- pesticides are pointless, bcause by then they’re already dieing or dead. The best solution is to keep the numbers down the rest of the year by keeping the soil from staying too moist- in California, especially, they’re a sign of overwatering. Physical barriers like weather-stripping can also help to keep them out of homes, but their bodies are flat and narrow, allowing them to slip through surprisingly narrow cracks.” Interestingly, we found more written about Lawn Shrimp on North American websites than on Australian websites. You can read more about them on the Museum Victoria website where they are called Land Hoppers.
wow – thats fantastic. Thanks very much for tracking that down.
Now that I know what they are, it all makes sense and I know what we’ll need to do to help reduce their numbers.
Much appreciated, and many thanks Daniel.
cheers,
Andrew.
Letter 2 – Lawn Shrimp or Househoppers
Sky Shrimp?
October 25, 2009
After a recent rain storm in the Los Angeles area, a friend of mine reported that there were thousands of the small insects(?) scattered all over her driveway and sidewalk. I’m usually pretty good at identifying the odd arthropod, but this one eludes me. They may be associated with a tall palm tree outside the house, but that can’t be verified.
It looks like a shrimp, or some larval form. Can you pinpoint this?
Sir Real
San Dimas, CA (East Los Angeles area)
Hi Sir Real,
These terrestrial amphipods are called Lawn Shrimp or House Hoppers. They live in shrubbery and are most fond of ivy. They ofter are not noticed until they enter homes in large numbers after a rain and promptly die.
Sky Shrimp Identified
I don’t know if my last retraction came through, so I’m duplicating the effort.
Very much like the last person who wrote-searched-found-wrote, I am in the same boat. Only after I wrote my question, I read through to another person searched after they wrote. So did I. Yes, your search engine is functioning well within parameters.
THANKS for the great site.
Sir Real
Letter 3 – Lawn Shrimp in Ireland
Subject: Strange looking dead bug!
Location: Ireland
March 15, 2014 10:56 am
Hi there found this weird bug dead on sofa..there were 2 of them! Founding n Ireland! Is this some sort of carpet beetle perhaps?
Signature: Ali
Hi Ali,
This looks like a terrestrial Amphipod, Arcitalitrus sylvaticus, commonly called a Lawn Shrimp or House Hopper. These Australian natives have become established in southern California as well as several other parts of the world. According to BugGuide, their range is: “Southeastern Australia (New South Wales and Victoria), as well as nearby areas of the Pacific, but introduced into New Zealand, the British Isles, Florida and California.” They are known to enter homes when their garden habitat is flooded due to rains.
Letter 4 – Lawn Shrimp or House Hopper
What is this bug
Hi,
Recently, I found 5 – 10 bugs on the carpet of my family and living rooms each day . They are dead and dried out. I live in southern California. Can you tell me what bug it is?
Many thanks.
Eric
Hi Eric,
You have a type of terrestrial amphipod known commonly as a Lawn Shrimp or House Hopper. According to Hogue: “During or just after a rain, residents in various parts of Los Angeles County are sometimes startled to find a number of these amphipods in their houses. The creatures are usually dead when found and are a nuisance merely by their presence. It is likely that the House Hoppers seek the dryness of buildings when their natural habitats become flooded.”
Letter 5 – Lawn Shrimp, in Connecticut!!!
shrimp beetle???
Location: Milford, CT
June 25, 2011 11:08 pm
I live in Connecticut and found this guy crawling on my floor. It was also making flipping movements like a shrimp! Never seen one before. Help!
Signature: freaked out
Dear freaked out,
This sure looks to us like a Lawn Shrimp or House Hopper, a terrestrial Amphipod native to Australia that has become established in California gardens and more recently, Florida gardens. It is especially associated with gardens that are well watered and have eucalyptus trees and if conditions are right, they can become very plentiful. See bugGuide for additional information. We doubt you will experience much of a problem in Connecticut with Lawn Shrimp, and it is our theory that perhaps you recently did some landscaping or purchased some plants from a nursery and that those plants may have originated in California, or possibly Florida. It is doubtful that Lawn Shrimp will be able to survive your severe winter and we doubt they will become established. This is most likely a single sighting and you should not be alarmed.
Letter 6 – Lawn Shrimp reported from Mexico
Subject: about 20 of them apear dead each morning.
Location: Cuermavaca Morelos Mexico
July 3, 2017 12:05 pm
Hello , just wondering what this bug is.
Thanks for your help
Signature: Fernando
Dear Fernando,
These are terrestrial Amphipods commonly called Lawn Shrimp or Househoppers, and they are an invasive species introduced from Australia. According to BugGuide: “These are rarely seen except when flooding or lack of moisture forces them to abandon their home in the soil in search for suitable conditions. At such times they often end up dieing on pavement or in homes and become a nuisance. Once they start appearing, there’s not much that can be done except to sweep them up- pesticides are pointless, bcause by then they’re already dying or dead. The best solution is to keep the numbers down the rest of the year by keeping the soil from staying too moist- in California, especially, they’re a sign of overwatering. Physical barriers like weather-stripping can also help to keep them out of homes, but their bodies are flat and narrow, allowing them to slip through surprisingly narrow cracks. Non-native; introduced probably from Australia along with blue-gum eucalyptus trees in the 1800s. First recorded in San Francisco, CA in 1967.“
Daniel, thank you very much for the information , indeed they look like small shrimp!!!!
I greatly appreciate your time.
Regards.
Fernando
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?