A couple years ago I would hatch chicken and quail, I live on a farm that's also a petting zoo and this time since my siblings are older and more interested in the science of things I have been showing them the process of chicken development in the egg because I'm doing it again. It's fun and easy and it's a really cool learning experience. I sit down with them and candle the eggs which is basically like an egg ultrasound. After about 3 days of incubation you can clearly see the embryo and the veins surrounding it. You can also see the tiny heart beating and if I could upload a video to glow I would because it is just so cool but I'm posting a picture instead. This is so fun to watch, after a while you are able to see the baby chicken moving and kicking around in the egg.