I’ve seen that behaviour too Nostaw and assumed they were grooming but I suppose they could be scratching or collecting pollen…they do get very messy rolling around in pollen don’t they?
There was some discussion about this in an earlier thread about mites.
If you type the word “mites” in the search box at the top of this webpage the various replies will be found for you.
Sparrow - Sue
Thank you Sparrow - Sue