Baby birds don't breathe until just before they break out of their eggs. Though you can't see them, there are tiny holes in the shell of a bird's egg, and these holes allow air to fill up part of the egg. So, when a bird is ready to hatch, it takes a breath, sucks in the air that was inside the egg, then breaks out of its shell. - bigsiteofamazingfacts.com; answers.yahoo.com; sciencebuddies.org
Baby birds don't breathe until just before they break out of their eggs. Though you can't see them, there are tiny holes in the shell of a bird's egg, and these holes allow air to fill up part of the egg. So, when a bird is ready to hatch, it takes a breath, sucks in the air that was inside the egg, then breaks out of its shell. - bigsiteofamazingfacts.com; answers.yahoo.com; sciencebuddies.org