Twins can have different biological fathers
In rare cases, twins can be different races.
Separated twins can live eerily similar lives
If a pair of identical male twins marry a pair of identical female twins, their children will legally be cousins but genetically be full siblings.
Women who eat a lot of dairy are also more likely to have twins
Twins interact with each other in the womb
Some conjoined twins can hear each other’s thoughts and see through each other’s eyes