My chi Chica hardly ever makes any noise. She may bark if someone rings or knocks on the door. My chi Coco barks at all noises. I have been shushing her all the time when she just barks at anything, and when I shush her, then she makes a low moan. She also moans at Chica to play with her and wags her tail at the same time. She keeps it up until Chica runs towards Coco for a chasing game.