Like many other animals, squirrels cannot tolerate being close to one another through most of the year. They would just as soon kill each other as share the same space. We sure had some scarred up squirrels this year!
In late Fall or early winter, however, they begin to exhibit much more tolerant behavior. As the winter mating season approaches, they become more playful and downright crazy acting.
I presume it is the lead-up to mating season. It hasn't actually started yet but they are a lot more lovey dovey.
I saw seven males all in a line following a female a couple of years ago! I should say I presume the seven were males since you cannot tell male from female just by looking at them. Well, that isn't always completely true either.
There are two mating seasons. Winter may seem like an odd time to mate, but it is timed so that the litter is born in late February when winter is ending and food becomes more abundant.
So if you see two squirrels like this, know that it must be love because it sure ain't normal.
I saw something in a catalog the other day that made me laugh out loud. It was a t-shirt that said, "I can't talk right now, the squirrels are watching."