The ravens near my house have always been pranksters. They used to follow me and Mack on our morning runs, flying from one tree to next until we left the forest. Mack was never very interested in them, but I always said good morning.
Biggie has learned that where there are ravens, there might be dead stuff. And if you chase ravens they fly. I keep him on a leash until we are past the houses, and especially the house of the neighbor who masticated her yard, where the ravens have taken to hanging around in her chewed up shrubs. These birds are smart, they know this dog, they know when he is tethered, and they love to tease him. Unfortunately, for me, one flew over and landed on the ground to my left and Biggie lunged from my right with all his enthusiasm and 65 pounds of twitch muscle, tearing my rotator cuff in the process.