advice on keeping the coop pest free

I saw 2 of what looked like red mites on top of the coop yesterday - they were abt 1mm long and lookes like small red spiders.   I peered inside at night with a torch and couldn't see any colonies.  The birds all seem happy to be inside and I coat the entire inside with a diatom slurry 3-4 times a year, clean everything out with a brush fortnightly and spray fortnightly with poultry shield and very occasionally use Jeyes fuid if things look extra mucky.  The chooks also get dusted with a mite powder every 2-3 weeks.

Can you let me know if this sounds like red mite or a red spider mite which apparently are different?  And is there anything else I should be doing to protect my girls?

Cat