What makes birds flock together when they fly?
This is a really good question! I will have to ask a birder friend of mine. Here is something that I found: Some researchers hypothesize that electromagnetic communication or even “thought transference” must be involved. In reality this behavior results from far less mysterious causes. Such movements are a prime example of emergent behavior: the behavior is not a property of any individual bird, but rather emerges as a property of the group itself. There is no leader, no overall control; instead the flock’s movements are determined by the moment-by-moment decisions of individual birds, following simple rules in response to interactions with their neighbors in the flock. First, I should mention why animals aggregate in flocks, herds, and schools in the first place. While there are many reasons, the most pervasive seems to be that it serves as a defense against predators. Having many eyes together ensures that at least some will spot a predator while others are feeding, snoozing, or look
