It looks like these babies are already fighting, and making up, while in the uterus! It is amazing how much we can see in the womb today with modern technology.
These images were taken from an MRI scan, or magnetic resonance imaging. The details that can be seen are incredible, especially the way these two little people are moving around trying to get comfortable.
It seems sibling rivalry has already begun in the womb, at one point one twin seems downright frustrated, and kicks repeatedly at the other baby.