Since their birth, we seek a point of difference between the two kittens. Everything is the same in those two! The spots at the same locations, the color of eyes, dress, etc..
It look of the veterinary view to find the details that differentiate them.

The difference is only on the right cheek of kittens. Indeed Fearghas has a continous mascara on the inferior line and Fëanturi has a discontinuous mascara on the inferior line !!!!!
Must find !!!!!!!
The proof of this picture: