Ranked by impact, not by how good it feels.
1. Fund or arrange neutering — this is the whole game
Everything else on this list manages a problem that neutering prevents. One unspayed female and her descendants produce a colony within a couple of seasons. If you do exactly one thing, make it this: find your local TNR group or low-cost spay/neuter clinic and either use it or pay for someone else to.
2. Learn what an eartip means before you trap anything
A cat with a small clip off the tip of one ear has already been neutered and returned as part of a TNR programme (Alley Cat Allies). Re-trapping that cat wastes a slot someone else needs and puts the cat through surgery-day stress for nothing.
3. Feed on a schedule, not continuously
Put food down at the same time and take the bowls up afterwards. Scheduled feeding tells you how many cats there actually are, makes trapping possible when a clinic slot comes up, and avoids the standing food that generates complaints from neighbours — which is how colonies end up being removed.
Be honest about what feeding alone does: it keeps cats alive and in a predictable place. On its own it sustains a colony rather than shrinking it. It is the thing that makes step 1 possible, not a replacement for it.
4. Provide winter shelter
A covered plastic tote with a cat-sized hole cut in one side, raised off the ground and packed with straw — not blankets, not hay. Straw wicks moisture away; fabric holds it and freezes.
5. Talk to the neighbours before they call anyone
Most colony removals start with a complaint, not a policy. A neighbour who knows the cats are neutered, fed on a schedule and not multiplying is usually a neutral party rather than a hostile one.
6. Do not take a healthy adult community cat to a shelter
Roughly 3 million cats entered US shelters in 2025 and 277,000 were euthanized (ASPCA). A feral adult does not show well in a kennel and is not a realistic adoption candidate. Neutered and returned to a managed colony, that same cat is fine.