as alot of you know i have an enormous cat run onthe back of the house. well although i have litter trays indoors jj, harry, oliver and nellie prefer to use the earth in the pen. when i got oliver he started to use the grass, so i have put used litter on the earth to tempt to use that, which he does. the only trouble is its very smelly. i regularly take the poo off, and at one time i was digging in the litter, but as soon as i do that olver starts to use the grass again. i just wondered if anyone could suggest a way that i could maybe disinfect the earth and stop the smell. i know you cant use house disinfect because of toxins, but its getting rather stinky up there. someone has suggested paving the grass area, but its so uneven with olver digging holes in the lawn and its a big area.