Yesterday I witnessed some very human-like behaviour between two of our local carrion crows (Corvus corone):
I was looking out of our kitchen window, which is on the second floor, and initially saw only one crow down on the lawn. This crow was holding something white in its beak, maybe a piece of bread. Suddenly, it looked around, and then poked a hole in the ground, popped the white thing into the hole, and then picked up a leaf and placed it over the hole. At that point a second crow flew down from the roof of our flat, landing on the lawn a couple of metres from the first crow. The first crow slowly walked off to one side while the second crow walked in a round-about way to the exact spot where the first one had stood. The second crow then picked up the leaf, laid it to one side and poked around in the hole. Having apparently satisfied itself as to the contents of the hole (it didn't appear to eat the contents), the second crow then replaced the leaf on top of the hole and wandered off.
It seems natural to interpret the first crow's behaviour as an attempt to hide the white thing from the second crow, but what intrigues me is the second crow putting the leaf back after it had a look in the hole. This seems to indicate an instinct to hide from the first crow the fact that it had had a look.