I know a dog that, if you've not paid attention to her water bowl and it's empty, and she wants water, will simply paw the rim of the bowl to cause it to overtu

I know a dog that, if you've not paid attention to her water bowl and it's empty, and she wants water, will simply paw the rim of the bowl to cause it to overturn, which makes a loud clatter on the hard floor. Once she then has your attention, she'll give you a look, as if it say "water, let's go." I dare say she trained us — after all, we didn't teach her to do that. And sure, it's simple … but she's still purposefully communicating a desire/intent. (She's a good girl, too.)