In an article posted by the Weed Science Society of America,
“Underground Gardening” by Earthworms, night crawlers are credited with purposefully collecting and planting that nemesis of allergy sufferes, giant ragweed, throughout the American midwest. Below you will see an earthworm "planting" a ragweed seed by dragging it into its burrow (photo - thanks to Denyse O'Leary):
Although I actively promote using earthworms to compost organic waste indoors as a way to keep it out of the garbage stream and reduce the accumulation of the plastic bags that collect the waste, I do not advocate releasing them into the wild, especially in Canada, where they have been blamed for some degradation of northern forests.
