Territory: Cats are territorial animals and they will often fight to defend what they believe is their territory. This is most common with cat fights that happen outside the house, where your cat believes another cat has encroached on their land. Alternately, a feral cat could believe your cat should not be here. But such fighting is also common among cats who live together. Cats mark their territories with scent, and your house is no exception. If you have more than one cat living at home, they will often fight about this issue.
Aggression: Some cats can be aggressive by nature. Male cats are especially aggressive and these cats keep fighting. Sometimes, they also dominate female cats. Your cat may need to act out their aggression by picking fights with their brothers and sisters or by causing a fight with a strange cat.
Rough play: Sometimes cats can be playing and it can get rough. Cats are rough when they play – this may look like aggression and fighting, but it is not. Still, such play could escalate into a fight or cause harm to both or one of the cats. In such cases, it is best to separate your cats if you can do so safely.
Cats are not pack animals, and they don’t generally enjoy living in groups, small or large. There are ways to make space sharing less stressful including: providing separate feeding areas for each cat, providing numerous water stations, and creating lots of quiet, private hiding areas for ‘me time’. Using cat-appeasing pheromone products (either sprays to use on furniture around the home or plug into diffusers) can help to reduce feeling s of stress and therefore reduce aggressive behaviour. These techniques will help with the introduction of a new cat or to reduce any signs of aggression in household that already has multiple cats.