Baby Squirrels in October?

Yesterday, October 4th, I watched a squirrel move her hairless babies from a squirrel box to a nest. After watching her move two babies I ran to get my camera. I don't have any photos of her with the babies in her mouth because once she caught me with the camera, she just yelled at me and wouldn't continue the task until I left. She waited me out.

First, I'm am so surprised that a squirrel is having a litter of babies at this late date. Is this common?

Secondly, I can't imagine why she moved them from the comfy box to the open nest, especially since it was about to rain. The box is near the neighbor kids' playset, but she made the decision to have the babies there, why move them now that it's getting colder and wetter.

Squirrels usually have two litters a year, one in the early spring and one in the fall. They move their babies a number of times to different nests and locations. It's usually because of flea infestation on the current nest, though sometimes they do it due to predators, ants or other annoyances.