How to make a feral/stray cat shelter - There's so many different options when it comes to building an outdoor shelter for cats, this is the simplest and easiest out there…. I'm not saying this is the best, but it's more than adequate to keep some feral/stray kitties warm this winter! :) *Other tips/options/considerations for this type of shelter... 1. You can use styrofoam or insulation board instead of straw. 2. ALWAYS use straw and not hay! - Hay soaks up moisture which makes the shelter cold