What to do with a robins egg?
You can definitely blow out a robin’s egg- I had one growing up. It will probably stink, so do it outside. I guess there’s a chance the inside wasn’t a liquid egg, but rather an embryonic chick, so there’s a chance you won’t be able to blow out the contents like an easter egg. You might see if you can see any shadowy shapes in the egg by shining a very bright light through the egg in a dark room. If you choose to blow out the egg, here are instructions- there are lots more online. Basically you make a small hole and a big hole in the ends of the egg. Put in a needle, break the yolk sac, and swirl to liquefy. Then gently blow the liquid contents out into a bowl. I’ve never done the last step of baking the shell, so I don’t have any advice about that.
I feed button quail eggs (about the same size as a robin egg) to my egg-eating snake. Usually I pierce the end of them with a needle to let the scent out (long story). If she doesn’t end up eating them, I eventually remove them from her enclosure. After a while, they dry up with just a tiny pinhole in the end. Another option: we went to a display/demonstration of Ukrainian Pysanky Eggs. Though they sometimes blow the contents out, traditionally they would leave them full. The website (at the very bottom of the page) suggests turning them weekly to keep them from exploding as the organic matter decomposes, until the eggs dry up.
