I finally have tackled the job of harvesting my fennel seeds. That is until I discovered the swallowtail caterpillar on one of the canes. I left the rest for it to munch on. While we were cutting the seedheads we found this:
This is what happens when you are a lackadaisical gardener and your onions and fennel go to seed at the same time. It seems that the fennel sent the seeds right up through the center of the onion seeds. Fun to look at right?