When Cats in the Same Household Don’t Get Along

A reader recently wrote to me about her cat not using the litter box. Like most people, she assumed it was a behavioral issue or a health problem. But when the vet ruled out medical concerns, I asked her to do something different: watch her cats closely for a few days and tell me where they spent their time.

What she discovered was eye-opening.

Two of her cats were spending most of the day sitting at the top of the stairs, just outside the bedroom. That happened to be where the only litter box was located. The third cat—the one “misbehaving”—was rarely upstairs at all. She was being blocked. Bullied. Intimidated away from the one place she was supposed to go to the bathroom.

Once this cat owner saw the pattern, we made a simple change: add one more litter box upstairs, and two more litter boxes downstairs, in quiet, easily accessible spots. (As a reminder, the golden rule is one litter box per cat, plus one extra.) Within days, the problem was resolved. The offending cat started using the new downstairs boxes and peace was restored in the household.

This scenario is far more common than most people realize. Just like dogs, cats living in the same household can experience conflict and often express it in very subtle, but disruptive, ways.

Here are five signs your cats may not be getting along, and what to do about it:

1. One cat won’t access certain areas of the house. 

If you notice a cat staying on one floor or avoiding certain rooms, it may be due to another cat guarding those spaces.
Tip: Add extra resources like litter boxes, food bowls, and comfy beds to areas the isolated cat can safely access.

2. Blocking behavior near litter boxes, food, or water.

Cats may silently guard high-value areas without a sound, just by sitting near them and staring.
Tip: Create multiple stations for litter, food, and water throughout the home to reduce competition.

3. One cat always hides or avoids contact.

If one cat consistently hides when the other is around, it may be out of fear, not preference.
Tip: Provide more vertical spaces, hiding spots, and safe zones for that cat to retreat without being cornered.

4. Hissing, swatting, or chasing.

Obvious, yes—but some people dismiss these signs as “play” when they’re actually serious social stress.
Tip: Interrupt tense moments with a toy or gentle distraction, and don’t force cats to share tight spaces.

5. Litter box problems.

A cat peeing or pooping outside the box may be trying to avoid a confrontation, not protesting out of spite.
Tip: Use the rule: one box per cat, plus one. Scoop daily and place boxes in low-stress, quiet areas.

Sometimes, resolving tension between cats is as simple as rearranging the house to give them all what they need. At other times, a little behavioral modification or professional help may be needed to rebuild trust.

In this case, all it took was understanding the social dynamic and respecting each cat’s need for safe access to resources. Once that happened, the bullying stopped, the litter box issue resolved, and the household returned to harmony.

These subtle shifts can help maintain harmony and reduce tension:

• Create visual barriers. Use furniture, cat trees, or tall plants to provide cats with more opportunities to move around without staring at each other. This can reduce tension in shared spaces.

• Add vertical territory. Cats feel safer when they have places to perch. Shelves, window hammocks, and multi-level towers let cats spread out and observe from above.

• Control the chaos. Sudden noises or fast movements—like vacuuming, loud guests, or children running through the room—can spark tension between cats. If the household is particularly active, move cats to a quieter space where they can feel safe and undisturbed.

• Try calming pheromones. Plug-in diffusers or pheromone sprays can help reduce anxiety and create a more peaceful environment. They’re especially useful in high-traffic areas or during times of change, like introducing new pets or rearranging furniture.

• Respect quiet zones. Give each cat space they can retreat to where no one will bother them, even you. Extraboxes or baskets throughout the home can provide those additional hiding places.

• Use scent to unify. Gently rub a soft cloth on one cat’s cheeks and then the other’s to mingle scents. It can subtly reinforce the idea that they’re part of the same group. Sometimes, resolving tension between cats is less about training and more about thoughtful setup—making sure every cat feels safe, seen, and supported. Once the litter box issue was resolved in this home, so was the conflict. With the right environment, even tense multi-cat households can find their balance again. Final Tip: The cat who hides the most or causes the fewest problems may be the one feeling the most stress and needs your support.