If I told you that flatworms had invaded France, you might say, c'est la vie. A worm is a worm, after all. But then I\u2019d tell you they\u2019re also known as land planarians, and you might think that sounds rather more alien. Then I\u2019d say they\u2019re also called hammerhead flatworms, and you might start getting nervous. Oh, and they grow to a foot long and release secretions from their hammerheads that glue them to their native French prey, the innocent little earthworms.