didn't know you used small, uncovered trays 
I don't Sarah and, more to the poiint, neither do my cats !

I simply thought that it would be more "PC" to allow Small Un-covered litter trays to have their say

For the record my cats use Extra-Large Un-covered litter trays from Pets at home, I do have a large covered one that I bought from a local pet shop which sits in the corner of the room functioning as a piece of abstract art which they've never been in the slightest bit interested in but I suppose that it's become positively "de riguer" for every home to have a piece of abstract modern scupture
Cheers
Leigh