Calling a raise on the river

[Hellmouth]

I've just moved up a limit and noticed that a lot of the players there will raise the river if they think that they have the nuts.

Example: Hero has QQ and is in late position. Hero raises driving out all but one other player.

Flop: Q,T,9 suits unimportant. I'm thinking that Ive got top trips and there is an unlikely (but not impossible) straight on the board. Villian Checks, Hero bets, Villian Calls

Turn: Some small card like a 3. Villian checks, Hero Bets, Villian calls

River: 8 Now I'm thinking "Crap any jack beats me and I got screwed because I couldnt properly protect my hand." Villian checks, Hero Bets, Villian Raises, Hero ...

Do you call this raise? It seems obvious that villian is representing the made straight.

Also, at any limits does a tactic like this start to work as a bluff?

I'll post the results later if anyone is interested.

Greg