Exerpts from the BBC article
Previous studies have shown that some earthworms will swallow plant seeds, while others appear to collect seeds, burying them in their burrows.
But it was not clear why, whether the earthworms were actually seeking rotting seeds, or whether they derived any nutritional benefit from the habit.
[...]
The earthworms selectively fed on slow-germinating, nitrogen-rich seeds and seedlings, actively ingesting the plant material, killing the young plant.
[...]
"They are invading several regions previously devoid of earthworms such as northern North America," says Dr Eisenhauer. Studies have already shown this can cause the extinction of some plant species, and Dr Eisenhauer's research provides one explanation why.
[...]
Wow.
Read the full article: Earthworms eat live seeds and plants, scientists find.