using a glass or metal file is best and sometimes soaking your hands in warm water beforehand can help soften the nails
Nails (and finger nails) have volume.
Finger nails are made of a protein called keratin.
No one invented finger nails.
Actually, finger nails contain protein (called "keratin").
By system, you mean category.. I'm not sure if you mean finger nails or like tool nails, so I'll give you both. Finger nails: Body parts Tool nails: Hardware
It is just like your finger nails. Clean them, cut them, file them, and if you want you can even paint them. But do not keep the paint on for too long or the nails may become yellow. (Please do not change first answer!)
Finger nails (and toe nails) are made of keratin.
Nails
yes
yes
A cat has thick nails to help them climb, hunt, defend themselves, and mark their territory by scratching.
It means that whatever it is is ... as thick as your finger is. This is a comparison to show you something's size.