During the day if I am studying or doing homework she will also bark when she hears someone coming up the stairs. It's as if she knows my bedroom is only for her and I to share and when she hears footsteps coming up she alerts me, which she doesn't have to since my stairs are so loud and creaky it's hard not to hear someone coming up haha. When she is home alone though, I have her in her ex-pen, she has never barked at me or given her "a-rufff" at me when I come home. She is only on duty when I am here with her.
It makes me happy to know that she is trying to protect me by alerting me.
My little guard puppy