Jumping worms, a group of invasive earthworms known scientifically as Amynthas spp., are causing concern among environmental experts in New Hampshire and other parts of North America. Unlike many earthworm species that benefit soil health, these worms—also called snake worms or crazy worms—are noted for their ability to dramatically alter soil structure, impact forest ecosystems, and reduce biodiversity.
These invasive worms consume the organic layer at the top of the soil, leaving behind castings that resemble coffee grounds. This behavior can quickly strip forests of their characteristic leaf litter, which is vital for native plant germination. The resulting changes in the forest floor can also negatively affect ground-nesting birds, amphibians, and invertebrates.
“Most earthworms in the northeast are considered exotic. They were introduced to North America in the 18th and 19th centuries from Europe and Asia though the trade of horticultural materials. Native plants in the northeast evolved without the presence of earthworms, and Northeastern forests have a characteristically thick layer of leaf litter and organic matter. Many native plants require this organic layer for their seeds to germinate. When jumping worms consume the upper organic layer of the soil, native plants slowly disappear and invasive species take their place. As the forest floor structure changes, other species suffer too, such as ground nesting birds, amphibians, and invertebrates.”
The spread of jumping worms is often linked to human activity. They are sometimes unintentionally transported through mulch, compost, topsoil, or potted plants exchanged at community sales or swaps. Experts recommend carefully inspecting these materials before introducing them into gardens or landscapes.
Identifying jumping worms can be challenging due to their similarity with other earthworm species. However, they can be recognized by their brown to grayish color with a smooth white band (clitellum) near their head and by their distinctive movement; they writhe vigorously when handled and move quickly across surfaces.
“Without humans unknowingly spreading them, jumping worms naturally expand their range slowly. Much of their spread occurs from human-assisted, accidental transport. Do not buy or sell mulch, topsoil, compost, or plants that you know to be infested with jumping worms. Before bringing these products home and introducing them to your landscape or garden, carefully inspect the materials for signs of jumping worms and their castings. Be especially careful when sharing plant material at community plant sales and swaps. Jumping worms will readily crawl in to reproduce within nursery pots. If you know you have jumping worms in your garden, it’s better to avoid sharing plants with other gardeners.”
Gardeners who suspect an infestation are advised not to panic; while there are currently no proven methods for controlling established populations of jumping worms, some mitigation steps include killing adult specimens by dropping them into soapy water or sand.
For more information about identifying invasive earthworms or addressing concerns related to home gardening issues caused by pests like jumping worms in New Hampshire specifically—the Ask UNH Extension Infoline provides practical support via phone at 1-877-398-4769 or email at answers@unh.edu.
