Sounds like lots of squirrels there! Nice.
When its real cold i,ve seen them out later in the morning. Sleeping in i guess.
Your last hunt they seem to be responding to a predator. Yes you,but if you watch them when hawk(s) around they will sound a warning and lay low. When they move its fast,and open areas sprinted across. A brace of squirrels is a good hunt for me. Have had plenty of hunts with none.
They will get busy when weather is more to their liking.