Squirrel battles

Squirrels seem to be really social animals.
I woke up to the sound of my dog barking quite loudly; As I got to where he was, there was the classic squirrel chittering going outside. So, I looked out the window, and there were two squirrels. One doing something in the bush and making noise, another standing on the grass, looking. After a while of that 2 more squirrels came out of nowhere and started chasing the first two. (I think). a weird battle ensued. Two of the squirrels were chasing after one poor guy who was jumping in an out of bushes trying to get away. And then there was the fourth kinda just standing there watching. Then a fifth black squirrel went though, but didn't mind the others. Very interesting. And I wonder what's in that bush.