Cat eating other cat's fur

I have two kitties. The younger short haired cat likes to eat the fur of my older long haired cat. She doesn't pull it off the cat but if there is some on the floor she goes at it.

I have never seen this before and have owned several cats.

I am wondering why she does this.

I've no idea why they do it but Jaffa is the same. He will eat Mosi's fur if he finds it on the carpet

I also have no clue as to why they do it! I only have one cat but she will eat the fur I have groomed off of her if I don't get it in the trash as fast as I can. I always wonder why the heck she does it

I don't have any idea why they do that either.
Elliott doesn't eat Gracie or Annabelle's fur, but when I comb him I have to bury the fur I get out as far down in the garbage can as I can get it.
If I don't, he'll eat his own fur.

Ferris licks up fur clumps off the carpet, doesn't matter if it is lint or someone else's fur - or my own hair, for that matter.

I'm sure this contributes to his record-breaking 6 inch long hairballs.