Last year, in the journal Animal Cognition, the behavioral biologist Thomas Bugnyar described a twist in an experiment he was conducting with laboratory ravens. The birds' job was to find bits of cheese hidden in film canisters, then pry open the lids to get the food out. One raven, Hugin, was best at this, but a dominant bird, Munin, would rush over and steal his reward.
So Hugin changed his strategy: when the other bird came over, he went to empty canisters, pried them open and pretended to eat. While the dominant bird poked around in the wrong place, Hugin zipped back to where the food really was. He was deceiving Munin.
Ooooh... That's just creepy how clever the little pinheads can be!
Nevermind other birds, like African Greys. Yikes!