to give you some insight I have been working on getting a new knee on June 20th. I have very little done in the way of permanent fence and pens done as of yet. I put the Ducks in the pen below every night and clean it in the morning after I let them out. as you can see I switched to sand. makes a huge difference in how wet and nasty the ducks make it. let it dry all day and rake out before they go to bed. this Duraliner needed a huge frame to make work. me and my son finished it tonight. its way taller as to prevent fighting from being to close to the ducks. that and it prevents them jumping out into the rest of the barn. oh yeah, this one got a layer of sand to. we'll see how it does in the morning.