Today while we were playing ball in a field another puppy ran over to play. All was fine until this other puppy had the ball and didn't want to give it back. Our puppy then snarled and bit him on the back, which he has never done to another dog before even when toys are involved. We apologised profusely to the owner, and she checked her puppy over and there were no marks or broken skin. We took the ball away and they then played happily. Our pup is 6 months old, definitely becoming an obnoxious teenager and has decided that biting is a good way to get what he wants. (Has occasionally gone for us in the house if he thinks we are trying to take something off him) Obviously now in the future we will remove the ball if another dog comes over as I suspect this was the trigger as he is ball obsessed. I just wanted to check that this isn't something we need to work on or can help him with in anyway? Thank you!