[Adastra] mites

[Heather White]

Hi there..  my friend seems to have a load of very small mites infesting 
his oak beams and i was wondering if anyone knew anything about this kind 
of thing?  They are very small (about 0.5mm diameter) so i can't give any 
more info but do have some as a sample if anyone has a microscope.  Any 
ideas would be appreciated as my friend and i have no idea whether they 
might pose   some sort of problem or not.  Thanks