Personally, I'm not really surprised. My goldfish begs when he's hungry by swimming up to the top of the tank and making a racket by thrashing around. When I feed him he's happy again and swims elsewhere.

I've had a rat who would throw one of his loudest toys up on the ramp and let it roll down, he'd do it as many times as it took to get my attention when he wanted out to play with me. He'd even do it, then look towards me to see if it worked, then do it again if I just sat there.

Animals can be a lot more perceptive than we sometimes give them credit for.