my dog Rocky has snapped at my mom on two occasions now. Both times he has been laying in front of her chair and she has gone to sit down. The first time I thought she maybe startled him but tonight he did it again and he was fully aware. I have no idea why he is doing this she is in no way stepping on him or hurting him in any way. She got very angry tonight and said if he did it again he would have to stay put up in my room or outside. He has also started to bully my moms dog who likes to lay down in her chair. I'm not sure if he is "claiming" her chair or what but he suddenly has an issue with my mom and her dog. Right now I am just keeping him from laying down in her chair but any advice on why he's doing this and ways to stop it are welcome!!