i put hay on the bottom, then cut a piece of plastic hardware cloth to break the fall of the egg, then on top of that some straw and pine shavings, my girls rearrange the material in the boxes, they all like to use the same one, once i found 3 girls in one box singing the egg song....i used golf balls, i recently got as a gift some of those ceramic eggs, the girls did not like them and kept rolling them out of the nesting box...they were like "THESE EGGS ARE FAKE, THEY ARE NOT ONE OF OUR EGGS!!" SO FUNNY