George was always with tidy with the litter tray but he was happy to go outside as soon as we let him out.

Milly on the other hand is very very messy.
She empties all the litter, into a pile on the floor. Does her business in the box and then throws just enough litter into the tray to cover her business. Leaving a pile of clean litter next to the tray !!!

My partner has suggested we leave her an empty clean litter tray with a small pile of litter next to it !!! sigh. At least she gets some exercise digging.