What is the technical term for when a butterfly emerges from its cocoon?

Do butterfly cocoons "hatch" or is there a better, more scientifically correct word for when a butterfly emerges from its chrysalis? If there are multiple chrysalises, when they open, could one call it a "hatching" and not have butterfly experts laugh?|||It emerges from the cocoon or chrysalis.|||NGAoldon is wrong. When the Caterpillar wraps itself in the silken cocoon, then Metamorphoses begins. When the butterfly emerges from the cocoon, Metamorphoses has already taken place. I'm afraid I don't know what we call emerging from the cocoon, other than 'emerging'.|||metamorphosis