Oh, we sanitized it the first time and treated the hens, coop, and run with anti-lice stuff. It didn't do anything. So this time we tried something else, and it's not likely to be effective, either. So we're going with permethrin, which won't even require us to clean the coop out again.

Usually, as long as they've got a dust bath with some wood ash, they can keep the lice under control on their own. I've been told that their prior owner didn't give them a dust bath, though.