I can now tell by his behavior when I return from work that he's done a dirty deed. I also praise him and reward him when all went well in my absence. Thanks for your help in advance. Sincerely, J.S., New Castle Dear J.S., Even though this is a lab, let's forget that for the moment. Assuming this is a fairly typical six month old dog, without any unusual idiosyncrasies or personality traits, given the facts you've mentioned there are some areas that are of concern to me which are probably having the greatest impact on this problem.
Dogs are highly social animals.
They evolved along with their social system which is based on a family or extended family unit. Puppies were with mom, or at the very least with each other, and played and interacted amongst themselves and with different components of their environment through each and every day. He being a young energetic, highly social animal is probably thrilled and excited to see you when you come into his areas. And he probably has very strong desires to interact with you at these times. You probably have to do some chasing to get to him, and even that little bit of interaction may be something he so strongly desires at that point, that he doesn't in that moment think about the negative consequences.