They do if they are a reasoning-variant. That doesn’t necessarily mean it actually needed to reason for many questions, your prompt + regular context could be enough to get a good answer compared to prior models where you’d absolutely have to put it into a reasoning-loop to get an accurate answer.

It’s on by default, in a way. You can probably prompt these models with “and don’t reason about it, just give me the answer” and probably get a comparably good response without it using reasoning tokens for many things.