So I'm the the process of making a tree stand for my two burdies (tookie and pika) I'm building it on the top of my bunk bed. It's going to be on the top bunk so I need something to catch there droppings. I plan on using plywood cause it nice and cheap. So I can etheir use (MDF, hardwood plywood, OSB) and I dont know witch one whould be safest to use