If you ever needed evidence that a crow is smart enough to mess with other animals, this video may light up your life.
In this action packed 1 1/2 minutes, an agitated cat is provoked from behind by a crow. Though the cat seems annoyed, it's attention is full focused on another cat on an adjacent rooftop.
The crow continues pulling at its tail until the cat is worked into a rage. It jumps to the neighboring rooftop and takes out its pent-up rage on the other cat. A fight ensues and the crow watches like a keen referee.
Studies have shown that crows have an intelligence similar to that of young human children, with problem solving skills and the ability to make tools.
They also, apparently, have a curiosity that compels them to fuck with other animals for fun. To see is to understand.