Ok, I went to Home Depot yesterday, and was speaking to a guy in the lumber department. He made it sound that if I used "untreated" lumber, insects/ants/whatever would burrow into the wood and have a field day. He said I MUST use treated lumber for building outside. So to confirm, most of you use untreated lumber AND untreated plywood to build your coops and have no problem? After you build, do you use any kind of wood preservative? Thanks so much, by the way I'm new here (have been lurking for awhile), and have gotten so much great info. My 4 chicks will arrive from Meyer on Tuesday.