How do i tell if my drive belts need replacing? on 2010 Toyota Tundra

I have a 2010 tundra 4x4. 44000 miles, I'm about to take it in for 45K service. Hoew do i tell if my drive belts need replacing?

2 answers
look for cracks in the v's on belts very easy to see
with that many miles on it if it hasnt been changed before I would change it