It looks like they are doing well. I remember with my first hive, I wanted to look in it every couple of days to just see what they were doing. If you ask 10 beekeeper how to control mites you will get 10 answers. I use screened bottom boards and try to avoid putting to many chemicals in my hives. I am on the west side of the state so moisture in the hive is our big enemy in the winter, so good ventilation I have found is key to limiting losses.