Sylvia only growled at me when she had a Jumbone. She could be eating a piece of steak and not growl, but the Jumbome is her favorite. Harley growls all the time. He NEVER bites, but sometimes I press my luck. Harley growls when he's sleeping and I get in his face. I like to snuggle with my dogs, but Harley doesn't like it at first. After the initial shock of me cuddling up to him while he's asleep he's fine. The vet said as long as he doesn't snap it's not a big deal. He said sometimes JRT's are very vocal.