Tire help

[Draekyn]

Ok, bike experts ;) This may seem kind of dumb, but I really have no idea.
How do I know when/if I need new tires for my MTB? I've had it for 3 years. Is there anything special to look for on the tire to know it needs to be replaced?
Thanks!

[Irulan]

tread wear and chunking out. knobs breaking off. Splits in the sidewalls......

irulan

[Draekyn]

Thanks! I just took my bike in for a tune up, and didn't look at the tires too closely. The guy at the LBS called me and said that the tire blew out after he fully inflated it. So I guess it was time to replace them.