Thanks go to Bruce Taylor for alerting me to this study.
As we know the Flatworms kill our native earthworms, but the university site contains some truly gruesome details about how they go about their murdersome business and how difficult they are to eradicate once they get established. It appears that the flatworms can reduce to 10% of their body weight for up to a year as they await another earthworm dinner. Perhaps the weight-loss industry ought to be sponsoring this survey!
More details, including how you can participate, are available via these links: