I've got two cats, both female and neutered. Cat 1- previously mild-mannered 4 year old, and Cat 2 - rather bouncy 10 month old. Cat 1 was harassed by Cat 2 when Cat 2 was a kitten, but over the last couple of months has been a lot more assertive - there's a lot of chasing around and rolling on the floor play fighting. No-one is hissing/peeing in corners or trying to leave home, so I've left them to get on with it. BUT, I've just been away for a few days and the person who came in to feed them couldn't get upstairs to change litter trays because Cat 1 stood at the top of the stairs, hissing whenever she approached. Cat 1 has also done this when I've had friends to stay, so she obviously feels threatened whenever people try to invade her territory. I'm wondering how to improve things as I'd quite like to be able to have guests access upstairs and indeed the catsitter. Do I need to make her more confident in her relationship with the kitten, or should I invite lots of people around so she gets used to sharing her home??