There's an unneutered black and white cat who often comes into our garden on Hindmans Road. He sprays a lot which annoys our own cat, and recently attacked a neighbour's cat who was visiting our garden. He seems pretty healthy and content, but we were wondering if it's worth trying to get him neutered. We would need to establish that he's definitely stray or feral first, which I gather you can do with a temporary collar. Does anyone have any relevant advice or experience with this?