Oh, thought of one. While out snorkeling, I scooped up a couple sea urchins to see if I could open them and get some fresh uni. It didn't really work out. Brought them into the boat and started to cut it open. I got it open without getting pricked, but once opened, didn't see the goods. Maybe too young, or wrong sex? I dunno. Basically, I just made a mess and killed the thing for no reason. That made me feel bad. So i won't do that again.