Normally February and and March are the best months, but yes the squirrels will chew them up fast. The best way to hunt sheds is to walk fence lines and places where deer have to jump. When they hit the ground the shock will help them drop there. i know one guy that found both sides in the same spot for three years and shot the same big a$$ deer twenty yards from there the next. I dont know if there is any real trick to it or not. I have always found the most of mine while farmin, along the edges of fields. Hope this helps.
Also the neighbor already found one shed in the ditch before december was over so they could possibly be dropping them early this year, or it was just a fluke.
Josh