The definition of an invasive species is one that is nonnative to
an ecosystem and whose introduction causes or is likely to cause
economic or environmental harm or harm to human health.

Eleven thousand years ago, northern North America was covered in ice. This glaciation destroyed native worms. The forests in that part of the world evolved without earthworms. With the onset of European settlers in the 1800s, earthworms began to enter North America again. Since that time, they have continued to be distributed and spread through soil redistribution, in plant pots, after being used as bait, and via mud on vehicles and boots.

On their own, worms move slowly. Their rate of movement
has been calculated at less than 30 feet per year. It would take
an earthworm over a thousand years to move just over 5 miles! It
is people who brought earthworms to northern North America.
About three decades ago, scientists in Minnesota and New
York noticed that the forest floors were changing. Since then,
studies have shown that some worms can have a negative impact
on ground-nesting birds and forest regeneration and increase the
spread of invasive plants such as garlic mustard.

From the 35th edition of “Worms Eat My Garbage”