I just started dating a girl and she owns to adopted dogs. A 2 year collie mixed female and a 3 year old red heeler mixed male. When I walk into her house they go aggressive towards me. They will jump and bite my arms and even have latched onto my rear end a few times. If I hand them a rawhide when I walk in they leave me alone. They only act this way when I'm standing. If I'm sitting in a chair or laying in bed they curl up next to me. Lick my hand and are just absolute babies. But if I get up to go to restroom or get a drink they feel the need to attack me.