I think its fear, but sometimes the signs point to aggressive. she always barks out the window at people passing, mainly its if they are walking a dog, or if they look like they are walking a dog. If people come to the house she freaks out barking, generally she stops when they enter the house and present themselves,after a few minutes of her pacing around. we do not have many people come to our house, but she does bark at people she knows . Some times the hair on her back is raised sometimes not. Its mainly its a quick "ruff.ruff.ruff.ruff" and nothing will get her attention. sometimes its a low growl b.c she knows im in the room and will tell her to stop. she just loves to sit in the living room on the couch and watch out the window and do this. The most logical thing would be to move the couch, but my husband insisted on buying this giant sectional and it literally takes up the entire living room and I cant move it. so back to my question. I really think she is barking out fear of the unknown. although she has also started nipping at other dogs lately. she only nips at them if they come near her, other wise when we are out she could care less when she sees them. The only reason I am asking b.c there was a episode of "its me or the dog" on tv(animal planet) that showed a dog (I think a american bull dog) that barked when people came over. the only difference (with my dog) was this dog would bite them if they came in. I dont want it to get to that point. So how can I approach this with our dog, since obviously everything we have been doing is not working.