I'm just wondering if anybody has any advice on aggressive puppies. Eleanor can be a terror and has been since I got her. She bites so much and I know at 5 months old puppies can be nippy but she's worse than that. She plays with my other dog Sully and he wants to play "chase me for this toy" but she ignores the toy and just plays by biting him. She bites at his infected ear and his eyes, which I'm really worried she will hurt him doing, and just about any other part of him she can bite. She is a resource guarder toward other animals and will take her bone into the other room and then come and attack him for his bone too if I give them anything. She sometimes bites at people, mostly me, especially hands, when she's excited but does not resource guard for people which makes it hard for a person like myself to correct because she doesn't do wrong when I take her stuff or put my hand in her food bowl. She is socialized and gets along with other animals except my sister's dog whom she will attack if we bring her to their house. She hates him for some reason but at the dog park she is too occupied to attack him so we've been having them play together there so we can work our way to them getting along in a less exciting place like at home. I already make her sit and wait for food and am working on waiting at the door. She will be enrolled in obedience classes once she is 6 months because I don't want to do the puppy classes for dogs younger than that as they only teach a few things she already knows like sit and lay down. I'm at the point where I'm looking at muzzles so she can't bite, but that doesn't solve her desire to bite constantly. I'm not really even feeling a bond with her because she has such a bad temperment. Sometimes I look at her and think how much I never would have picked her out of a litter if I had gotten her from a litter of puppies because she can be so nasty. I'm hoping working together in a structured obedience class helps a bit.