yes squirrels are one of those critters that are in constant motion,the red squirrel took hours and a few days to get a few decent shots of as they are nervous and really fast,plus a long lens but i found getting him used to hearing the camera noise helped a lot,if i can do that with a wild subject it helps my resident mocking bird is used to me and the camera i can get pretty close to him these days,the eastern grey squirrels are more bold though the black form is very common in most of ny these days wish i could have gotten a better picture of him but it was a tree area so i could not get any closer:(