I believe every animal should be fixed. I have a whole soap box about breeding, but I'll leave off for now. If this behavior is new, it sounds as if something is going on. What has changed in the household lately? New child, new routine, a child that was home all day now in school, some change in routine. Frankly, it sounds like he is totally bored and looking to expend energy. Is he alone for a large part of the day? Is he played with (vigorously) and walked every day?