Identifying Tiny Household Bugs?

Can you identify this bug found around the house, but there is an infestation in daughter's upstairs bedroom. The photos aren't very clear because they are so small, I had to zoom it to see them. The biggest ones are less than a pin head. It looks like they have white on their backs, similar to a carpet beetle, but think they are too small to be? I can't see the white marks with the naked eye, just in zoomed in image?

They seem to be attracted to joints of wood/furniture and funnily enough my daughter's hair straighteners (maybe the cracks again?). They are not particularly really around the windows. We've had them now for a few months. We have tried sticky strips, deep cleaning, and bird mite power/spray (we had birds nesting under the eves, and also chickens in garden). But I don't think they are bird mites.

I have seen similar bugs around house, but only one or two. My daughter's room is infested. I would be do grateful for advice. My daughter has had to move into the lounge!