Free · about five minutes · pen and paper
Most intercat tension is not a personality clash — it is two or more cats competing for too few of the things they need, in too few places. A resource map makes that visible in one pass through the house: what exists, where it is, and whether it is actually enough.
International Cat Care states it as a formula and repeats it across their conflict, multi-cat, and cat-friendly-home pages: one of each resource per cat, plus one extra, positioned in different locations. Cornell and the ASPCA give the matching n+1 rule for litter boxes specifically. It is the single most repeated, most sourced rule in our protocol library — see the full record in the protocol library.
The rule is about space, not just quantity. Three litter boxes side by side in one bathroom read to a cat as one resource, not three — a cat guarding the doorway blocks all three at once. The extras only count if they sit somewhere a cat can reach without walking past a rival.
One per cat, plus one extra — in different rooms, not lined up in a row.
A cluster of three trays in one bathroom counts as one resource, not three (iCatCare). Uncovered, away from full-length windows, cat flaps, noisy appliances, and busy thoroughfares. If one cat can sit where it watches the only usable tray, the extras are not actually available.
One per cat, plus one extra, in separate rooms or on separate levels.
Cats are solitary feeders, not a group that shares a bowl comfortably. Bowls away from corners so the eater can watch the room while eating. If one cat only eats when the other is shut in another room, that is a resource gap, not a preference.
Several stations, away from food, wide and filled to the brim.
Water next to food reads as one checkpoint to guard, not two resources.
Perches and high resting spots throughout the home, each with two ways off it.
A single high perch with one entrance is a trap, not a resource — a cat can be cornered on it. Add private, low, hidden places too: under beds, inside boxes, behind furniture, left undisturbed.
At least two entry and exit points per room a cat spends time in.
One doorway means one cat can guard the only way out. A cat flap only one cat can use safely, or a room only one cat can reach, both count.
Walk the house room by room with a pen. Write down how many cats you have once, then count each resource against it. “Need” is always cats-plus-one — fill it in yourself so the sheet works if you get another cat later.
| Resource | Need (cats + 1) | You have | Separate locations? | Shortfall |
|---|---|---|---|---|
| Litter boxes | ||||
| Feeding stations | ||||
| Water bowls | ||||
| Resting places at height | ||||
| Exits / escape routes |
Print this page (Cmd/Ctrl+P) to fill it in by hand — the diagram and buttons are hidden on paper, the table isn't.
Any row where “you have” is below “need,” or where a resource exists but not in separate locations, is a real gap — not a maybe. Cross-reference it against where the tension actually happens: a cat that stares, blocks a doorway, or ambushes near a specific box or feeding spot is usually guarding exactly the resource that's short. Fix the shortfall in that spot first, not the one that is easiest to reach.
A map that comes back full — every resource at cats-plus-one, spread across the house, with no single doorway controlling access to any of them — rules out competition as the driver. That matters, because it means the tension is coming from somewhere else, and more bowls and boxes will not fix it.
A resource map is a management fix for competition-driven tension — staring, blocking, displacing, ambush without contact. It is not a treatment for two things:
We will say this again if you take the free read: those two situations get refused a written plan, not sold one.
A room-by-room count of everything cats compete for — litter boxes, feeding stations, water, high resting places, and exits — checked against the one-per-cat-plus-one rule from International Cat Care (iCatCare). It turns a vague sense that the cats don't get along into a specific list of what's actually short.
iCatCare states it directly: one of each resource per cat, plus one extra, positioned in different locations. Cornell and the ASPCA give the same n+1 rule for litter boxes specifically. It is the most repeated, most sourced rule in our library.
Fix the resource gaps first — add the missing boxes, stations, and exits before anything else. If tension continues after the household genuinely clears the one-per-cat-plus-one bar, that is worth a closer look, not more shopping.
No, and we will not pretend otherwise. A resource map is a management fix for competition-driven tension between cats who have not injured each other. It does not replace a veterinarian for medical soiling, and it is not the tool for a household where a cat has already been hurt.
A full resource map is one step of the resource-map protocol in our library. If the shortfall isn't the whole story for your cats, take the free read for the fuller picture.