About a week ago, a fox squirrel who was probably between six and eight weeks old approached, followed, and chirped to my wife as she was finishing up some gardening just after dusk. He looked confused and was clearly in need of help. Long story short, after looking for advice here and other places, we brought him inside and he spent the night in a box with fabric and a warm bottle in our hallway. The next morning, he was happily reunited with his mom (who we've known well for about a year). Since then, we've seen him playing in the early morning, and we've seen him in the nearby fox squirrel tree/emerging from the dray.
Unfortunately, tonight, we saw him near dark in the same situation -- a bit listless, seeming lost, and hanging out on the ground with my wife and I, then some neighborhood kids. We had to leave for about an hour, but we had a neighbor watch him while we were gone. The neighbor reported that he'd sort of sat still in a low branch for a while, then may have climbed up to his nest but she wasn't sure. When we returned, we didn't see any sign of him or of any trouble, so we're hoping he found his way home again.
My question is this: is this behavior at all normal for a squirrel that age? Could his mother have rejected him? What should we do if he comes back again? We want to do right by this little squirrel, and also by any other squirrels in trouble in our area. We contacted a local rehabber during his first visit, and they said we did the right thing by taking him into the house that time, but we're wondering what to do if this behavior continues?
Thanks for your help.