Stork Bites?

Tristan was moved to a crib today, joining his brother in the free world.  Tristan was 4-5, while Landon checked in at 4-4.5.  Both boys have what they call a stork bite on the back of their heads.  It is basically a type of birthmark, which will fade with age.  We found Landon's first and thought it might be a way to tell them apart, but nope, they are identical of course!