Our Holly can be quite reactive. We noticed it when she was 5 months old when our daughter returned to live at home temporarily. Our daughter’s room abuts our family room where Holly’s crate was and we spend a lot of time. When the door would open and K entered, Holly would crouch and bark loudly and repeatedly. I would startle too which I’m sure didn’t help. Fast forward to 10 months old and she is now reacting by barking loudly and repeatedly when startled on a hike, in the dog park and at our family camp when people enter the room even when she knows them well. We are stumped on how best to manage this behavior. Otherwise she is a very well mannered dog with improving recall, crate trained and calm. We often get complimented on her pleasant and calm demeanor.