help! kitty's biting her nails

It's probably normal for little McKinley (a 2 year old female) to groom between her claws, right? She'll sit down and spread out her claws and lick between them. Recently I've seen her seem to be biting and pulling at her claws with her mouth. I always tell her no when I see it, mostly because it appears painful and it's hard to watch, but today she vomited and I found what looked like a whole claw nail in her vomit. There was no blood on any of her feet, but after seeing her bite at herself, I really believe she pulled a claw out. Could this be and, more importantly, does anyone know WHY??

Thank you for any help!

What you see is normal - my Loki looks like he is
ripping his claws out at times - might look painful to you, but it is not. You see their
claws "shed" and they are helping along with the
process. I occasionally find sheddings in the shape of a claw that he on the carpet.

It is normal for them to do this. Two things you can do is make sure you keep her nails trimmed and make sure she has some sort of scratching post she likes. When they scratch the sisal or carpet, it helps to shed thier nails.

Mine do this regularly to their back feet. They seem to view it as just another grooming chore, since they usually do it when they're doing a full body "detail" bath. One of them spits out his claw sheaths like he's spitting watermelon seeds for distance.

I'm so relieved to hear that this is all normal....