This fact about Mary-Kate and Ashley Olsen will shock you ...

OK, so this may or may not be BRAND. NEW. INFORMATION.

But we did not know this and now our minds are blown!

Mary-Kate and Ashley Olsen are one of the most famous sets of twins in the world. Any girl born between 1980-2000 should definitely know who these two are.

But surprisingly, our favourite twins AREN’T IDENTICAL TWINS!

It turns out that they are actually non-identical twins - better known as fraternal twins!

Buzzing out right now because they look like EXACTLY the same?

Fraternal twins are actually conceived from two separate eggs in the womb, making it very unlikely the two kids will go on to share the same features, but Mary-Kate and Ashley did!

This is news to us, but we're sure there are some fans out there that knew this due to the fact that Mary-Kate is around an inch shorter than Ashley.