Probably one of the 'clover mite ' ilk. They are often reported inside homes. They can easily come through screens and any tiniest void around windows or door.

Try to keep grass and other vegetation cut back from around the home and sprayed with nothing stronger than insecticidal soap. The soap will keep these small animals at bay. Inside, a sponge and a bowl with a mild vinegar solution will do the trick.

OK, now I am totally creeped out and itching all OVER. Gah!!! I searched on clover mites and did NOT like what I found. I live in the redwoods, with bark everywhere around me, and wood siding on my house, and I'm gonna die now ............... I also live right next to a river, and I'm not willing to try to inundate everything woody around me with poison. I'll just have to learn to live with these things. I don't have much 'vegetation' around the house, a rose and some lilies on another portion of it, but there's nothing in the area where I find the mites, other than the 1 new rosebush outside in a barrel (and it's pretty small, and doesn't touch the siding).

Heh. At least they aren't the Large Brown Spiders that are seasonal around here and find their way into my bathroom shower stall. They're the size of silver dollars and I'm SO NOT a spider lover... Lots of screaming ensues!

Thanks rhizo_1 for letting me know.