Squirrels cubed

I was driving down the avenue the other day and movement in the silver birch to my left caught my eye. I slowed and stopped. Sitting on a branch about five feet above the car was a squirrel peering down at me with bright eyes and a tail like a bottle brush. I watched it for a few minutes when movement in the sycamores at the end of the avenue caught my attention. There was another squirrel scampering around among the branches! I was so excited because I had never seen two squirrels together before. I knew there had to be more than one squirrel and, like mice, the fact that I was seeing one meant there were many more in the trees, however this was my first time seeing two together. Just as I was getting over my excitement, I saw another squirrel higher up in the sycamores. The squirrels in the sycamores were bigger with bushier tails than the one in the silver birch so could it be a juvenile and the others adults - even parents - perhaps? I don't know, but I was excited and once more I bemoaned the fact that I didn't carry my camera in the car. When will I learn?