Sticky-board varroa count

I put in a sticky-board three days ago and took it out today. That's it on the left. When I took out the tray 3 days ago, there were about 10 bees in the space below the screen bottom of the hive. I looked carefully with a flashlight to see if there was a hole in the screen (there wasn't). I don't know how the bees got in there. There had been some before when I had taken out the tray for inspection. Maybe they get in around the tray's edges; after all, it doesn't fit perfectly. Anyway, I think the bees get their nourishment through the screen from their sisters in the hive. Naturally, I wanted to get them out before putting in the sticky-board. First, I left the tray out for some time, but no one flew out. I used my bee brush, duct-taped on a stick to reach, to try to brush them out, but only got a couple. I put honey on the tray and put it back in place hoping to attract them off the screen and then I could pull them out with the tray, but they didn't fall for it, so, tante pis for them. You can see them on the sticky-board. You can also see the pollen and other debris that fell through the sceen in 3 days.
Here is a close up of one of the squares on the sticky-board. The dark oval shapes are varroa mites. There are 4 in this square. I counted a total of 56 mites. Over 3 days, that equals 18.66 mites/day. According to all the online sources, this is within safe parameters at this time of year, so I won't treat. As has been mentioned before, some beekeepers never treat, believing in survival of the fittest and trying to select for survivor strains.
My girls are still going through the syrup quickly. They are also busy foraging, bringing back white, orange and red pollens.