I used 'mite solution' for the first time last fall. Prior to its use I had lost 23 of my 30 hives to Varroa mite. Although I had earlier used Apistan, I did not want to continue using it. I placed the mite solution in with grease patties in the fall, again this spring. A month ago I checked for Varroa, both in drone brood and with Apistan with sticky boards, and found NO Varroa. I don't know why it works, but from my experience, it does work, and the bees are once again healthy and busy in our gardens.