I have four house cats. They are truly house cats, having never been outside except for trips to the vet. They have seemly zero hunter instrinct. I have never had a problem. In fact, Timber tends to torment them for his own amusement and they mostly ignore him. That said, I would never, ever leave them unattended when Timber is not locked in the cage. Accidents can be fatal or expensive and traumatic if nothing else. I wouldn't risk it for anything.