Max liked to play with his piddle pads when he was a pup, but he grew out of it.
Sounds like Mia has pent up energy with a little bit of separation anxiety. Instead of the xpen, try giving her one room. I wouldn't give her run of the house. Trainers often say that dogs feel overwhelmed when they have to "defend" an entire house. Boundaries give them comfort, but maybe an xpen is too small for boundaries for Mia.
Limiting freedom also helps with potty habits/training.
__________________ Kristin, Max and Teddy  |