If you think about it, identical twins are pretty crazy - two people who look exactly alike. It goes further than that though, identical twins have the same DNA. So what does that mean if a pair of identical twins marries another pair of identical twins and then each couple has a kid? Well, things get even crazier, and that is clear on @ThePeterTwins' Instagram account.
The page is run by two men, both named Peter, who look exactly alike, except they aren't identical twins - in fact, they aren't even brothers - they're cousins. Their moms are identical twin sisters and their dads are identical twin brothers. Each couple had a child and both chose to name that child Peter. Because their parents' DNA is the same, both Peters' DNA is incredibly similar - so much so that on a DNA test they'll come up as brothers. They are what is known as quaternary twins.
The boys tried to break it down in a recent post.
One question they get asked often is if they have the same birthday, but remarkably, one Peter is four months younger than the other.
You can see more from The Peter Twins, including an explanation on why their fathers' are named Pedro and Peter and how they got their names, on their IG page.