I noticed some insects that are not mason bees going in and out of the reeds in the mason bee house. Not sure if they are hoverflies, honeybees, or some other insect - they are striped yellow (maybe a hornet? Not sure, but smaller like hoverflies or honeybees, not "wasp waisted" in shape).

Anyway, should I be concerned about this or just leave things alone? Not sure what I could do, if I cover the holes the masons can't get in. Appreciate any advice you can offer.