I assume what I am about to describe is pretty common but this behavior just developed in Ella over the last couple of weeks and has become more pronounced.
When I get ready to go out the front door to go to work Ella will start nipping at my heels and clothing. Since it is winter and going outside is a whole production she has ample time to prance and spin around and bite at my clothes and shoes. It is not overtly aggressive, it is mostly playful. But I sense their is an element of "I don't want you to go and I am going to try to stop you" to it. Is she demanding that I stay, or just excited about the activity at the door? FYI-This happens just after she has had her morning walk so she knows she isn't going outside.
This is the same dog that took several months to bond with me and who never gives me any sort of greeting when I come home. Strange.