I recently got a couple of dumptruck loads of chipped pine bark & pine needles from the local utility co. after they trimmed back the trees from area power lines. Am building my FIRST coop and run, and everyone here seems to agree the run gets picked clean of vegetation pretty quickly. Would a couple of inches of this chipped pine bark/needle mix work for the run? Seems fun to scratch in, good drainage (sandy soils beneath it) and should be mold/pest free as it is new. Any thoughts? It will obviously decompose over time; should I leave it and add on top, or rake it all out and replace occasionally?