Have you ever stepped on a 'goat's head'?

Horrible stuff! Put the dampers on a lot of bike rides.

But interesting, the plant is quite famous for medicinal purposes.

And yesterday, I heard on a public radio station that they are releasing a weevil that destroys the seeds. Apparently, one plant can produce 600-800 goat heads. The weevil can’t survive the winters there. And they don’t consider an invasive introduction.