Laughing as I read your post and type this. Allie whirs, and I think she is the only one out of 8 that do it. She always gets so wound up, runs through the house, 'climbs' the door frame, whirring as she goes.

Then, I have the chirper. Gus chirps or meoups all the time. As I go to pet him, as I hold him....this little sound that only he makes. Adorable.