Animals experience the "Uncanny Valley"
The uncanny valley is that strange feeling you experience when you see something that is almost, but not quite, human-like, such as animation in a film or video game, or robotic movements that mimic our own. You may even experience this feeling when you see other primates. Some folks have suggested that "the valley" may be what caused us to kill off Neanderthals (although I'm still looking for a more reputable source on this topic)!
Long story short, turns out that a recent study suggests that monkeys are also disturbed by almost life-like images of other monkeys. Marc Bekoff gives some nice explanations for why animals might be hardwired to look for stimuli that match expectations of what other members of their species should look or act like (or as another scientist points out, these likenesses may not be visual at all, but could be sound or olfactory-based). Read it all here!
What does this mean for robo-squirrel?
Fish can play
Play in animals is typically described as behaviors that serve no immediate function, and that occur spontaneously in a safe environment. Scientists discovered a cichlid repeatedly attacking objects in the bottom of his tank, to no apparent end. I'd love to see further research exploring if this behavior is a frustrated response to an unstimulating environment (similar to repetitive behaviors seen in other captive animals), or truly play.
Can you tell ravens and crows apart?
If you find it difficult, you're not alone. Both species are very chatty, and often live in overlapping areas. Here, a short video will help you tell the difference between their calls, and decipher the meaning behind them. If that's not enough to help you out, you can download a crow vs. raven identification packet from the Cornell Lab of Ornithology here!