Can anyone help, please. My daughter and her boyfriend had litter brothers, 18 months old, both neutered. Sadly one of the cats was hit by a car and killed 5 days ago. They are totally devastated. Having 2 female cats myself, who are very territorial, and who can't stand each other, I have suggested they don't get another cat. I thought their remaining cat, Norman, might become very stressed if they introduced a new playmate for him. I have just read a post on here that has suggested that male cats are less territorial than females. Is that correct? They are obviously missing Norman's brother dreadfully and they are very concerned that he is lonely as the brothers were very close, playful and adored each other. I would like to be able to give them accurate information, so they can make an informed and sensible decision. They are most likely to get a rescue cat by the way.