not had probs for a long time ,but had some once when I bought some cages in, they looked spotless but must have had the mites ,as said they can live in the shed/under roof felt ect. take some getting rid,i removed the cages and cleaned with smite the mite, nearly every day for a good while,only put birds back in year after not had none since ,best spot to find em is under nest felts if there present, also scrub with old type vim,but don't know if its still available, best to check close new birds/ equipment when buying in atb.