Long intro, if you're interested: I've been putting food out for a feral kitty I call Karen (long story) that we've seen in our "back 40" which is a large section of our 1 acre back yard which the municipality does make us cut but we cut it long and not as often so it's meadow-y. We think Karen lives outdoors at a house a couple doors down. We don't believe they take care of her at all as we've seen her hunting in our back yard in weather *very* much below zero F. We don't want to ask them because frankly they're a bit scary. Anyway, she eats the food every night, although if we get too close to the back door she runs away (and comes back to finish).
Actual question: I want to make one of those feral shelters with two Rubbermaid totes like on Alley Cat Allies. I know the bedding material needs to be straw and I understand why. But in the gap between the inner and outer bins, would polyfill (like from pillows) do as good a job as straw? I ask because we have a lot of old pillows lying around and I feel like this would be a better use than just throwing them away, IF it would provide good insulation. The shelter will be well sealed and have an entrance tube so I don't think there's a danger of the polyfill getting wet.
Thoughts?
Actual question: I want to make one of those feral shelters with two Rubbermaid totes like on Alley Cat Allies. I know the bedding material needs to be straw and I understand why. But in the gap between the inner and outer bins, would polyfill (like from pillows) do as good a job as straw? I ask because we have a lot of old pillows lying around and I feel like this would be a better use than just throwing them away, IF it would provide good insulation. The shelter will be well sealed and have an entrance tube so I don't think there's a danger of the polyfill getting wet.
Thoughts?
The big thing is to make sure you add the insulation not just around the 4 sides in between the 2 bins, but also on the bottom between the two bins AND on top between the two lids. Also be sure to put the whole shelter well up off the ground (it helps w/temp control, & snow & rain issues). We also add a piece of plexi over the front to also help w/wind, snow & rain buffering, plus the kitty can see out too-which they seem to love!). We buy a cheap piece of plexi at a home store that we slant "a-frame style" against the entrance if that makes sense (we attach it by drilling 2 holes in the top of the plexi piece - & drill 2 holes in the outer Rubbermaid lid - & attach it via zip ties. And if you have access to electricity-- Karen would (in the winter) I'm sure love the electric pet outdoor heating pads in her shelter (but they do need to be pet ones - not human, which are too hot--& outdoor rated ones). But even w/o a heating pad - I'm sure Karen will be VERY grateful!!! (& warmer & dryer!!!). 
