All of our dogs have been rescue dogs so they tended to be somewhat set in their ways when we got them. Although they were still puppies, they had already got used to doing as they pleased. One of them was reasonably well behaved anyway. The only thing she was sneaky about was eating rubbish on the street. She had all sorts of tricks to go eat a discarded takeaway and all sorts of other unsavoury things. She definitely knew that she was not meant to eat these things but she did it anyway. Our other dog was very badly behaved. We kept her on a leash all the time because of that. She did not like other dogs at all for some reason. If we had allowed her near them she would probably have tried to fight them. To be honest, I think she was probably just scared of them. Perhaps she had some bad experience with other dogs before she came to us. She was also very easily distracted and easy to scare. If we had allowed her off her leash, she might have run away and not come back. This would not have been because she did not want to return. It would be because she would keep getting scared by loud noises or distracted by food and would not have been able to find her way back to us.