I have the same problem... I think squirrels are actually a lot smarter than what we think they are they see that big .30-06 or .270 and they know, "awwwww [beeep] he ain't gonna try and get us with that thing boys lets go grab some grub" but they see those two little bitty numbers .22 on your gun and they say "Oh **** boys go home! Go home nowww!". Now for seriousness this is not the case, previous commenters are correct in my personal opinion they really seem to be cold natured, towards the end of the year and begining of the new year they seem to really stay inside a lot until mid day when it is warmest and even then on some days they just arn't moving, I know a month before deer season here I could go out and kill 10+ squirrels in an hour or two but in the past week I havn't even seen any so I don't even go out, I'd rather stay warm than waste my time.