A simulation reveals how conjoined twins Abby and Brittany Hensel's body functions after siblings spotted with newborn baby.

TLC stars Abby and Brittany Hensel have always said they wanted to be mothers, but since the conjoined twins share reproductive organs, a new report has questioned whether it’s possible — and which 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 ...