It makes sense that identical twins would have the exact same DNA, right? Spoiler alert: Not always! Here's why. Identical twins (also called monozygotic or MZ twins) are conceived when a single sperm ...

A new video out of London’s Center for Fetal Care shows twins fighting. Not that interesting? Well, it gets better because these twins haven’t even been born yet: an MRI scan shows the beginnings of ...

From Romulus and Remus—the myth of the twin brothers who founded the city of Rome—to the synchronized speech of Australia's "Twinnies" Paula and Brigette Powers, identical siblings have long inspired ...