I know some people consider them to be pests but I love them. We have several crows that live in our neighborhood, and there's a threesome that share a nest in our neighbor's tall pine tree. I did a little research and found out that the "extra" bird is probably an older child, hanging around Mom & Dad's nest to help out with the new babies. Neat!!
They snatch dog food from our dog's bowl sometimes. I don't even mind, it's too amusing to watch one of them distract the dog while the other one swoops in to steal from her. And she can afford to share a little with her avian neighbors!