"Ed Hayes" wrote in message

If have 2 feral cats in our yard which we feed and take care of.

If you can capture them (in, say, a racoon trap) then the best favor
you can do them is to take them (while still in the cage) to a vet.
The vet can put the entire cage in a box with anestetic gas (to knock
them out without having to handle them). Then they can spay/neuter
the cats, give them shots (vaccines, rabbies, etc).

It will be easier to catch them in a cage when it gets colder and they
get more desperate for food.

Spend $150 on them. You'll never do better for them if you do that.
The diseases they can get are horrible and the remedy is simple. If
one (or both) are female, then they'll never get pregnant, and you'll
be reducing the cat population (and you'll be reducing the chances
that they'll develop cancer later). If one (or both) are male, you'll
again help to keep the population down, plus reduce their desire to
fight other cats or become terratorial. Usually, once they are
neutered, they will be more likely to be friendly with you. But it
does depend on how old they are. The sooner you spay/neuter them, the
better.

This winter I would like to build them a place where they can stay
which will keep them relatively warm.

A well insulated shelter should be all they need. You need to create
a space that will be kept dry, and have a small entry/exit portal (ie
wind-proof). Most important - they need to accept it. You'll never
be able to force them to use it. It can't be anywhere where there's
lots of people-traffic.

I don't know if it's worth the effort to create a space for them to
sleep and wait-out the winter vs creating an enclosure for placing
food. You will find that just keeping water and soft-food from
freezing solid will be a challenge. I've messed around with several
different heated bowls in an enclosure the past few winters to come up
with something that works.

We've turned several ferral cats into the most tame, lovable house
cats you could imagine. Once they come home from the vet, we keep
them in a room for several weeks to get used to people. They still
like to be indoor/outdoor cats, so a cat-door is all they need.