Cats in multi-cat households have a lot of social dynamics going on. Since cats evolved primarily as solitary predators, being housed in close quarters can cause stress and negative interactions. Even related cats do not always get along well all the time.
Because cats are highly food motivated, they will usually eat together with little aggressive behavior even when they don’t get along very well. However, when there is aggressive or house soiling behavior present anywhere in the house, you can reduce these issues and overall feline stress by having multiple feeding and water stations that are not in direct visual contact between cats. For example, put one food and water bowl around the corner of a cabinet or doorway in the kitchen so each cat can eat more privately. Or you can feed one cat up on a counter or table.
Having litter boxes in separate locations in the house (not all in the basement) also allows cats to reach a litter box without having to go near another cat. Some confident cats will lie on the pathway to the litter box and the less confident cat will not want to go around it to use the box and will find another location to eliminate.
Multiple elevated resting places throughout the house makes cats feel safer and increases their perceived territory. Cat trees, hammocks, bookcases, and even stacked cardboard boxes can give additional needed safe resting places.
Did you know that staring is a form of aggression in cats? It can be the first step toward a possible “rumble”. Often we don’t notice the staring cat in our house, but we do see the other cat that responds to the staring with a growl or hiss and then tend to think that cat is the “naughty” one.
Body language is important- for example ears forward usually means happy or calm cat, and ears back means an upset cat; laying on the back is not submissive but rather a defensive posture so the cat can use its back legs to rake its opponent’s belly.
Overall, to help keep the peace in your cat family, look at optimizing their feeding and resting places, and if cat squabbles are still occurring, it is time to see your veterinarian for behavioral advice.