You're right, Carole. There MUST be a female in heat somewhere. Since cats are territorial, that's why you smell the odor around your yard. A whole male hanging around can wreak havoc on indoor cats. All you can do is just clean it up as best as you can.

Any way you can find out who owns him and talk to them about getting him neutered. That'll stop the behavior all around.

Sorry you have to go through this, Carole. It's a menace, especially since it's affecting your cats. Hang in there!!