Hi, we are building our first coop/chicken run and have a question for you experienced folks out there. We live in a raccoon infested area. Our run is approx 12ft x 16ft x 6 ft. We screwed in (and buried about a foot deep) 1/2 inch hardware cloth. But what kind of material do we use on the top? Is chicken wire too flimsy up there? Should we use more hardware cloth? Something else? Is the top to prevent raccoons or to prevent hawks (we have both) from entering? Also, the location of the chicken run is a little unusual... Within the enclosure is a young sequoia (giant redwood). The diameter is about 3 ft right now. Any thoughts on how to work around the tree? Thanks!