We have just had two rescue male kittens. We had them at 9 weeks and they are adorable. We have an existing female cat who puts up with them. So far so good. However, it is three weeks now and whilst Kitten A is house trained, Kitten B is going wherever he damn well pleases. It's probably territorial, but that's no comfort when I get the Dettol out yet again.
I have had cats all my life but never had one that does this! All advice gratefully received.