[Pebbles82]

Ha ha. They do funny things. The best thing for a litter tray is Chinchilla bathing sand. It soaks up pee well. I am not sure what kind of wood pellet litter you had but she maybe saw it as something to gnaw on.

You mention her penthouse bedroom. Is she in the hamster heaven? Normal behaviours for a hamster are to bury hoards under their nest. So to encourage normal behaviours and avoid a stinky mess, it works better if they have a house that is open underneath and sat on top of the substrate. That way they can bury the hoards under the nest and burrow down a bit and keep cosy. And the nest stays clean.

If it is the hamster heaven, it works best with the penthouse and external tubes removed - they can also nest in the tubes and that gets messy too. She may have a hissy fit for a couple of days if they're removed, but if you add a house at floor level as well she will probably move in. It needs to be big enough for a large cosy nest though for winter,and dark inside.

Something like a shoebox house is fine. Cut the base out of the shoebox, keep the lid as a lift-off roof (so you can check inside without having to take the house out so the nest doesn't fall apart), and cut a hole at one end of one of the long sides, for a door (that means the opposite end is darker).

She would probably just move in and build a new nest there if you put plenty of torn up strips of plain white toilet paper in a heap in the cage (they take some to the house to build the nest).

If the house is large-ish they sometimes move their pee corner into the house at the opposite end to the nest, but that's ok as you just put the litter tray inside the house.