So I started throwing eggs, with no reason at all, and wondered what happened if you threw eggs underwater. And when I threw it, a chicken spawned! Really crazy! I'm pretty sure that wasn't supposed to happen. I read about and it said that it was supposed to leave a trail of bubbles only.
Well on minecraft for computer, its the same. Chickens have a small chance of spawning when you throw an egg. I do this in my chicken farm (uses water)