Baby Chicks Chirp Even Before They Hatch

We think of chickens as mindless egg layers, or bird brains. Considering Mike the Headless Chicken, you may be forgiven for thinking so. But the process of reproduction, even when it relies basically on instinct, is quite complex and amazing. Hormones and instinct cause a hen to go broody, meaning she devotes everything to her clutch of eggs, even to point of not eating. Cartoons depict broody hens as being surprised when their eggs hatch. Real hens know when that's going to happen, because the chicks actually start chirping! The hen gets excited and cheers on the chirping and the pecking until the baby chick is out of the egg. All that commotion encourages the other eggs to hatch, regardless of the fact that they were laid on different days. After all, it would be difficult for a hen to keep up with chicks when there are remaining eggs that need to stay warm. This new video from BBC Earth is from the series Secret Life of Farm Animals.  -via Damn Interesting