Twins and their Famliy
Chapter 10: Wombmates
It is commonly believed mirror image twins have finger, palm and heel prints that are mirror images of one another. But that belief is not true. The prints of any pair of identical twins are more alike than are the prints of two unrelated people, with a high correlation of loops, valleys, whorls and ridges. As with all identical twins, however, the details of hand and foot prints in mirror image twins are not identical—nor are they mirror images.
Contrary to popular belief, a trained German Shepherd police dog can unerringly distinguish the difference in scent between identical twins. There is probably no epigenetic basis for this. It is thought to be due to their exposure to different infections throughout life.