15. Twins start interacting with each other in the womb
The University of Padova recently discovered that twins are as close in the womb as they are outside of it. At 14 weeks of gestation, twins were seen reaching for each other. Four weeks later, twins in the womb touched each other more often than they touched their own bodies. The twins were gentle to each other and made distinct gestures toward each other.
16. Twins can be born weeks, even months apart
The record is 87 days apart!
Source: Wise Geek