How to breathe while doing the Butterfly. The breath occurs when your arms are pulling through the water and they come down to your hips, the head comes out of the water naturally, take a quick breath right before your arms recover. As you're breathing it's important that you exhale in the water, you don't want to have your head too deep inside the water, or too high above the water. Your head should be right on the surface of the water so it's easy for you to come out and to take a quick breath and bring your face back in as your arms recover.
When breathing in Butterfly you don't have to bring your head out all the way to the point where your feet sink down to the bottom. You really need to bring your head out just enough to take a breath so as you're breathing in Butterfly, you can just bring your head out with your chin right above the water and then bring your face right back in as your arms recover. That's how we breathe in Butterfly.