Except for the rare occasion Mercury escapes but that's only for a couple of minutes, the time it takes for whatever idiot holds the door open to get into the bushes and retrieve him.

When I adopted my guys from the Vet, he said, "I don't normally let anyone adopt our cats if they're going to let them go outside." So I told him they'd be innies. I learned the hard way that innies/outies don't last as long, although my Tobias lasted 10 years. The average for outies is 5 years. My Tobias was one tough little guy. He decimated my fish pond. 😢 Tobias was a feral kitty who I fed and then adopted, having him neutered and giving him a place in my home. But he always insisted on being a free range kitty. Had I known then what I know now, I would have made him stay inside. It would have cost me a few nights sleep but would have been best for him healthwise.