Thrown Chicken Egg Spawns

1. I threw one egg into a pen and it gave birth to nothing
2. I threw a second egg into the pen and it gave birth to a single chicken
3. I threw a third egg, which hit the baby chicken I previously hatched, and that egg gave birth to 7 more baby chickens

I was able to duplicate the issue and made a 10 second clip of it in creative mode as well. So it's not just a survival issue.