Have had success power washing the little **** out. Can splinter the wood a little, but easily sanded back out and so worth watching them drown. Have been dusting the house regularly but missed the knots under the perches. Have now sprayed them with mite spray - available at farmers' shops. (about £7.00) Am going to paint with Cuprinol Shades as soon as it's dry (2010 maybe), will that kill them too or will it just look pretty?