If you can't trap, you could spray him with the hose if you don't want him around. They *HATE* water (duh) and it's a non lethal way of making him move on. Then there's the super scary shopping bag at the end of a stick swished around while you hiss like some kind of cat eating devil....
Make sure there isn't any food available for him outside either (chickens too). If you have food out something will come for it if there's nothing available most critters move on.
If you decide to feed him and let him stay just keep in mind you will likely attract more strays, which means stray kittens if you don't trap spay/neuter release. You'll also probably see a few cat fights between strays and house cats and there's the potential for your cats to pick up a number of diseases. Unfortunately it would probably be for the greater cosmic good to trap him and have him humanely euthanised. I worked at an SPCA where only 10% of the adoptable cats found homes. (adoptable - young, healthy and tame. If they didn't meet that criteria they were automatically listed to be put down.) I hated working in the cat room, it was so sad...
Make sure there isn't any food available for him outside either (chickens too). If you have food out something will come for it if there's nothing available most critters move on.
If you decide to feed him and let him stay just keep in mind you will likely attract more strays, which means stray kittens if you don't trap spay/neuter release. You'll also probably see a few cat fights between strays and house cats and there's the potential for your cats to pick up a number of diseases. Unfortunately it would probably be for the greater cosmic good to trap him and have him humanely euthanised. I worked at an SPCA where only 10% of the adoptable cats found homes. (adoptable - young, healthy and tame. If they didn't meet that criteria they were automatically listed to be put down.) I hated working in the cat room, it was so sad...