Tuesday, January 10, 2012

Gammarus – Large Flea Shaped ‘Bugs’?

Gammarus flea like crustaceans
I have had several enquiries recently from people experiencing an influx of a ‘mysterious’ orange brown flea shaped creatures. They have been found in garages and homes in large numbers. All the calls have originated in the North Island of New Zealand.

These creatures are gammarus which are not insects but are shrimp like crustaceans. There are more than 200 species of Gammarus worldwide and several in NZ. They are much larger than fleas but have a similar body shape, being flattened from the sides. They also have long legs and can hop in a similar way to fleas. In many parts of the world Gammarus are known as sand hoppers. Their normal habitats would be sea beaches, near rivers and lakes and below rocks and leaf litter in gardens. They need moist conditions and die quickly if exposed so they are usually under rocks or other cover.

Gammarus do not bite and are not normally a pest but the recent warm and moist weather in the North Island of New Zealand has encouraged numbers to boom. As they spread and try to find new places to live many people have experienced them moving indoors. Gammarus will die quickly in the dry indoor conditions and most callers have described finding many dead.

Ring type treatments with spray insecticide and/or soil insecticide granules will reduce numbers and reduce the likelihood of them infesting a home but they are only an occasional pest and do not cause any harm.

What do you call a happy sand hopper?
A hoptomist.


  1. Have the gammarus been found in the US? I have recently seen a bug that resembles what you re showing in Georgia.

  2. There are species of gammarus found in leaf-litter and beaches in almost all parts of the world.

  3. We just found 15-20 by our back door in Gainesville, Florida. Thank you for the information because we were truly at a loss as to what they were. There has been a tropical storm and lots of rain this week so your description as well as the photo fits the bill. Again, thank you for the information.

  4. I've found about 30 dead bodies to what I thought were giant fleas! We just moved in a place where the former tenant had a dog, and that was my reason for thinking this way. I've not found any alive, so that's good. I myself have a cat and dog. I found two Grammarus in my bed (ick) and one in my bathroom and the rest are in the corner that backs up to the deck where there is much moisture. My guess is they want the moisture? I live in southern California.

  5. I have been finding hundreds of dead ones each morning in my office at my warehouse. No clue where they're coming from. Just a nuisance to have to sweep them up ever day.

  6. I've found loads around my basement flat dead, and have seen and even hit me as they ping up across the room. I also thought that they was large fleas or some form of shrimp insects and not very nice one being the reddish colour they are.pleased to know what they are from East Sussex area England



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