Crows are really smart.
I watched them use sleight of 'hand' to trick each other last week: Crows randomly store food in case it get's scarce later. Crows are also thieves. They watch each other store food and then steal it. But once the victim realizes its food is being stolen, it will pretend to stash the food wherever it's been stashing it, while really hiding it in it's chest feathers. Then it goes elsewhere and hides it there instead.
I got to watch one do this about five times. He'd do the fake, glance over his shoulder, and fly off to hide it elsewhere. Tricky.