Mmm
We have a litter tray for Small Cat, who is pretty-much an indoors cat, and Big Cat has always made his own arrangements, involving shrubberies
BC was very ill last year and we gave him his own tray for a while, but once he was better he started going outside again. but the combination of he Landlord's gardener cutting back all the bushes in the back garden and the cold weather has seen him quide liderally squatting in his sister's litter tray
Since he does much smellier poos and wees than she does, this is Not Good.