I never know if I should fold these

[pokernicus]

I think it's a bit of a toss-up and depends on your read. You're behind to any Ace except A6 and A8, and villain's decision to wait for the turn to raise is usually indicative of strength. On the other hand, the pot is laying you 11:1 to call the river. If I knew something about villain and thought he was reasonable, I'd fold. Otherwise, I might just call to see what he has and get a better sense of this play.