Sketch for my next piece about mirror image twins. 25% of the world's identical twins are also mirror image twins, when the fertilized egg splits late (around 9-12 days). The twins have the same DNA but have small mirror image differences such as opposite cowlicks (swirl in the opposite direction), opposite side birth marks, mirror finger prints, mirror dental problems, and they are sometimes opposite handed. What I found the most interesting is that in some instances, one twin may be right brain while the other is left brain, which is what I based my illustration on. In theory, they are mirror image twins with opposite personalities.