[matese]

11 week old pup is playing, they get excited, growl, mount, nip / bite, it's all playing. My puppy females would mount their toys & the older girls, growl,nip / bite, all play. As lovetodream advised, you have to teach the puppy biting is not acceptable, what ever command word you use must be consistent, meaning, the same word MUST be used when the biting needs to be stopped. I would say "no biting" when my puppies would get very excited and bite hard. It's all just playing, and being a puppy, not being aggressive. As far as age for getting him neutered, I suggest speaking to your vet. I never owned a male puppy but had family and friends that did, they were all small breeds, theirs were neutered between 5 to 7 months.