In message , Rod Speed
writes

Feral cats won't use it, you watch.

I think this is a problem of description, always assuming Steph does not
live under a bridge. Steph describes the cats as feral strays, but they
must be one or the other, not both. Feral cats are domestic type cats
(i.e. not true wildcats), but born in the wild with no human contact.
Steph describes the cats in question as being dumped, so they are
strays, not feral, although subsequent generations of dumped cats may be
feral.

Either way, strays and, eventually, most feral cats will respond to
human contact, such as food and shelter. None of which addresses
Steph's original question. My answer would be to attempt to domesticate
the cats first, that is befriend them by supplying food and water, then
worry about shelter. Cats are clever enough to find shelter.
--
Graeme