How do primates keep their fingernails and toenails trim?

[Simfish]

Just wondering (after all - they don't have nail clippers) :)

Oh - and is growth rate ever affected by how much hair/nail there already is? (I doubt there is - but apparently it seems that hair seems to grow faster after being cut, is this true?)

 

[Moridin]

Primates do not need to actively keep their fingernails and toenails in trim because of general wear and tear.

 

[Ivan Seeking]

Also, do they bite their fingernails when nervous?