QR Code Link to This Post Try putting their litter box outside or you could take it a step further and sprinkle some of the litter box remains around your fence line if you can ( might not be possible) Do a thorough search of your neighborhood. Look under things, look through bushes and look up around trees and such. Put their info on any local Facebook pet groups that are in your area. Place their info on the Nextdoor app also. Please be aware that if your cat goes outside , there are predators ( animal and human kind) , there's the sad chance of your pet getting hit. Lots of worries. Oh also visit closest Humane Society frequently. Best of luck to you!