I use wood shavings as well. I put a lot in because they do seem to scratch to the bottome fast. To help prevent broken eggs you can put a cardboard square in the bottom. A little bit more cushion than a wood bottom. The Excelsior pads work great, but are over a $1 a piece. I will admit I just put some in, but only because we've had a few shell-less eggs lately. When the new layers get it together I'm going back to cardboard. I hate cleaning out an eggie nest! blech