My bees are too healthy

I've left treating for varroa a little late this year, but my bees seem healthy -- almost too healthy. They are still occupying supers and I'm having to remove them before treating (with Apistan this year since resistant varroa aren't quite here yet). There are so many bees, it's turning what used to be a quick job into a more elaborate one involving double and triple trips to apiaries as thunder is in the air and heavy showers come just when they are least expected.