Tiny white mites in house

[FlyingFish]

What are these tiny white mites in my house? They look like bits of dust crawling around slowly. They don't jump and they are around half a millimetre long - much too small to take a meaningful photo. I don't seem to be allergic to them. They appear at the beginning of September each year and fizzle out by new year. Local council said dust mites but all the literature says dust mites are invisible, plus why are they only visible for half the year? They are not booklice or spider mites as other websites suggest. The rooms affected are slightly damp but not really bad.

[terambulan]

Doesn't sound too healthy according to this website:

http://www.onlineallergyrelief.com/dustmite/du stmite.html?gclid=CJqxw9mj_pYCFRyS1QodkTfbXg

[jenniprice]

They're not silver fish are they?
We used to get them in our toilet at uni as was really damp.
They used to die out in winter as was too cold for them, plus we brought some powered stuff to get rid of them.

They sound a bit small for silver fish and as they're white probably not, but just thought I'd mention them.