'I'm not stupid.'

In this case, he's actually thinking more of the boys - he hasn't been eating much for a while but he knows they'll complain like motherfuckers if they don't get fed regularly. He looks out of the window.
Of course you do. You wouldn't be here otherwise.
'They'll be back soon, it gets dark pretty quickly up here. Unless they're trying to make a run for it. Get yourself something if you like, sounds like you've had quite a trip.'