top of page
  • Heather Raithby Doyle

Jumping worms are wriggling their way closer

Updated: May 8, 2023

By Heather Raithby Doyle

There is a relatively new and wiggly threat to our local ecosystem. Jumping worms (Amynthas agrestis), also called crazy worms, Jersey jumper, Asian jumping worm, or snake worms, have been spotted in Toronto, Hamilton and Windsor.

For gardeners, it’s worth being aware these invasive worms, and their poppy seed sized eggs, can hitch a ride in soil, mulch or compost. For this reason, it’s safer to buy plants grown from seed in trusted soil sources (such as from the Blooming Boulevards plant sale). Beware of gardeners offering plants dug from their gardens or wild spaces in infested areas. Moving a plant from your home to a cottage, for example, is also not recommended. Landscapers, bait companies, and traces of soil from tires and boot treads can also be responsible for the worms’ spread.

Photos - Top left: Asian jumping worm,; top right: A jumping worm cocoon surrounded by soil particles. Carly Ziter; bottom: Josef Gorres, University of Vermont.

One jumping worm can multiply into masses as they are hermaphrodites, meaning they reproduce without a partner. While this sounds like something out of a horror movie, it’s worth noting if you see a large worm this spring, it’s likely to be a nightcrawler aka common earthworm ​​​​(Lumbicrum terrestris) which is also invasive but less damaging to the environment. Jumping worms hatch from eggs and will be small and difficult to identify this time of year.

By late summer the jumping worms will be larger and distinctive. Here’s what to look for:

- a smooth, light coloured band near the head, called a clitellum, that goes ALL the way around their body (other worms have a raised clitellum that only goes part way around)

- a large size up to 20 cm

- wild thrashing when agitated

- the ability, like geckos, to drop their tail

- the soil will show dry, coffee like grounds (instead of small mounds like other earthworms)

The impact on soil health is why jumping worms are causing concern. Jumping worms live only in the top few inches of the soil. They have voracious appetites, consuming 95 percent of the leaf litter in a forest, for example, along with seeds. This stripping of the forest floor alters the composition of the soil, leaving it bare and nutrient poor in the fall. Come spring, it has become inhospitable to plants, insects, and creatures like salamanders relying on rich, and slowly decomposing leaf litter. If this wasn’t bad enough, due to the change in structure, the soil becomes vulnerable to erosion. Gardens and lawns are equally susceptible to damage.

Above left to right: Abundant leaf litter on natural forest floor; bare soil in forests invaded by jumping worms; castings (feces) of jumping worms resemble coffee grounds, giving the soil a grainier texture Photos: New England Forests, Michael McTavish

Birds do not eat the jumping worms, although, potentially on the bright side, moles do.

Right now the best offence is good defence, and knowledge about how to stop the jumping worms from finding a new home in the first place.

-Check potted plants and soil for tell-tale granules

-Ask your nursery if they are aware of jumping worms and what they are doing to make sure their products are not contaminated

-Clean your tools, shoes, and vehicles before and after travel

-Rinse roots before planting if you have any doubts

-Make your own compost

-Use leaf litter from your own property rather than picking up from municipal sharing programs

A simple test can also be conducted if you think you have jumping worms. Clear a small area, and pour a solution of ⅓ cup of powdered mustard, mixed with 3.7 litres of water. This will bring all earthworms to the surface for investigation.

Sources and for more information:


bottom of page