Dear Christopher Cat: I have indoor pet cats, but I feel sorry for the feral cats outside that don’t have such comfortable lodgings. Many of them live in the woods around my home, and I worry about them during the cold winter months.

I’m thinking about building or buying them a shelter. Can you recommend some options?

Christopher Responds: Let me introduce you to Alley Cat Allies, a one-stop resource for all things related to feral cats.

View photos of feral cat shelters you can build or buy at www.alleycat.org/resources/feral-cat-shelter-options-gallery/. You’ll find building instructions for all skill levels and links to finished shelters available for purchase.

Position your shelter on a wooden pallet, not on damp ground, and line it with straw, rather than hay or blankets, which hold moisture.

Situate the door away from the prevailing winds, and cover it with a flap.

Camouflage the shelter with paint or leafy branches so it blends in with the environment.

Check your shelter regularly to be sure it’s in good condition.

If the cats in your area haven’t been sterilized, work with your local humane society or feral cat group to trap them and have them sterilized and vaccinated for rabies. Then return them to their environment.

Most veterinarians, when they spay and neuter feral cats, remove the tip of one ear to make the sterilized cats easy to identify. If your local feral cats have intact ear tips, have them sterilized before breeding season begins in late winter, unless you yearn for even more cats to shelter.