Cats nails don't grow long the way dogs do, they shed in layers... thats why they "claw" and scratch everything... to try and knock off the layers..  Sometimes when you cut them you will see a whole layer of nail sheer off, it FREAKED me out! I was like, OMG! I Broke the nail!!!!! 

  But its just a layer shedding off... if they don't have a means to aggitate the nails they cant naturally shed those layers and their nails can get pretty gross... Hence tearing up your doorways and expencive furniture! LOL
