What I didn't know is that they can be a little bit spiteful. Scientists recently found out that they are able to recognize human faces and hold a grudge against the ones they don’t like. Hitchcock feelings, anyone? Well, in order to study the crows, they had to be collected and properly tagged. The scientists who handled the birds quickly fell out of favor with the crows. The next time the researchers entered the enclosure they were greeted by the crows divebombing and attacking them! If the same researchers came back wearing a mask that the crows hadn’t seen before, though, they were left alone. It also appears that the crows conspire with one another and share information about which humans they don’t like. Crows who were absent when a particular researcher had handled the other birds would still respond with hostility upon seeing the scientist at a later date. It's probably a case of either communication or simply going with the flow (a classic mary-goes-with-the-others kind of thing), I think.