That isn’t a typo. Alas, I didn’t make it up. I just heard it on a Science Friday podcast about how invasive worm species are destroying soils in the northeast US. It seems that they turn patches of forest floor that were once full of organic material into bare patches. These are forests above the glacier line. Presumably during the last Ice Age the hundreds of feet of ice killed off the native earthworms, so you generally don’t find them in northern soils.

The invasive species are from Europe and Asia. The venerable nightcrawler is a European import. The speaker said that most of these imported worms came either in the ballast of ships or in plants brought over by immigrants. Native species aren’t moving northwards the way the invasive ones are and given the northerly range these worms have in their native habitat they wouldn’t be expected to move that far north, so global warming may be affecting them. Hence, global worming.

Give it a listen. It’s fascinating: Science Friday March 23, 2007 Earthworms.