Our 6 hens live in an old stone stable block with wooden partitions (with bark still on). It has a cobbled floor! A friend stored timber in one stable for 10 plus years. The place has been infested with mites so I had to get rid of all the mitey timber I could and have sprayed the wooden walls with Smite and dusted with hens with DE powder x 3. I notice they are still itching though and now wonder if, perhaps because I can't possibly clean out all the dust and dirt and engrained stuff between the cobbles I should just give up and get them a swish wooden hen house that I can keep clean. Seems weird though when hens have made do with old farmyard buildings for centuries that I cant make it work? My next question is do the mites live outside in the grassy run they've currently got ( as I cant think where else to station the a new hen house if I do get one!). To be honest, the mites were so bad I was badly bitten myself as was my husband when he took a chain saw to the tree trunks! Any advice or comments much appreciated (we're in the UK).