I have one cat and 4 trays, she uses all of them at any one time. All of them are the same tray and the same litter.
I was having issues with one of the trays not clumping properly so I chucked it all and changed brand last week. However it's still not clumping properly but it's fine in all of the other trays.
The dodgy tray is on the half landing and closest to the front door and next to the wall of the downstairs toilet. We have no issues with damp, it's not cold, house is well insulated so I'm a bit perplexed.
Anyone able to shine any light on this??