Lol, that is a wonderful discovery, Serendipity! I truly had a much needed laugh at your thought process, too. Thanks for that, btw.
Congrats on discovering your sixth tadpole; I can imagine what a huge surprise that must have been for you and your family. I believe that the little one must have hatched after its egg was attached to the river rock.
Hee-HEE!! I wonder if you may find a few more surprises in the upcoming days.