Thank you - I ended up acquiring some proper foam in the end. Another question I had was, I'm getting about three and will probably be keeping them in a rabbit/guinea pig hutch (padding the ceiling, adding a pan of dirt or sand for dust bathing, adding appropriate litter of course) and I just wanted to make sure they'd have enough space, it's approximately 3x1.6'. I know the usual space requirement is 1 square foot per bird, but in a smaller cage than most will there be any problems? In other words, they'll have a bit more than 1 square foot each but I wanted to make sure it'd be enough. Thank you!