Question
Hello Jack, I live in Scotland in a large, old house which only has single glazing (as its old and listed we're not allowed to swap it for double glazing.) we moved in a year ago. Both home reports which were carried out before we moved in said that some rooms were slightly damp but no causes eg damaged guttering, leaks, rising damp etc were found, they thought it was just because the house had been unoccupied and unheated for over a year.
We've never noticed any damp or mould but the house is cold and in the morning there's loads of condensation running down the windows.
Ever since I lived for a short time in a very damp flat 15 years ago I've been absolutely paranoid about tiny little house mites appearing, as I couldn't get rid of them then and when I moved out, ditched every single thing in the flat and started over again. I've lived in several places since, and as I mentioned moved into my house s year ago and have continued my obsession of regularly inspecting every single thing I can to check for these things.
2 weeks ago during my usual obsessive checking, I found loads of them. Loads. Like moving specks of dust. In a cupboard and all over a laptop I hardly use. Queue frantic checking of the whole house and I found loads more, in a few rooms, especially in my toddler's room, which is actually the room I always check the most.
For the first week I did nothing but clean and vacuum, ive been spending hours washing and rehashing every fabric item at 60c and been spraying insecticide with permethrin (checked it said it was safe for kids once dry.) I've steamed beds, carpets etc several times.  I've made myself quite ill with all this and with the stress of it and have been researching on the Internet as much as possible. I bought a dehumidifier and have been running it on full power for 24 hours a day in an attempt to get the humidity down below 50%  to try to dessicate these things but it's either not going to work until I buy another one for downstairs or it's just going to take longer, I'm not sure - still not quite worked out how best to use it. I'm worried that if due to the fact our house is old etc I just won't be able to get the humidity down enough to get rid of them - does it absolutely have to be under 50% or should it work if I can get to 60%? (I have to by a hygrometer but judging by when my unit turns off I think I may reach around 60%.)
Please help, I'm going out of my mind :(

Answer
Jayne,

I think you have diagnosed the problem exactly right. These are mold mites (also called grain mites), see http://www.livingwithbugs.com/mold_mites.html for some id and control info about these mites. They are associated with humidity or dampness in general. In an older house without good insulation and central heating they will be very difficult to control. The good news is that they are completely harmless so the real issue, I believe, is to concentrate on managing your anxiety rather than managing the mites. Short of moving to a modern house with central heating there's not much that can be done to completely eliminate the dampness, mold and mites. Reducing the humidity (dampness) as much as possible will help but the difference between 50% and 60% is probably not significant.

Jack DeAngelis