Liz shows the field day participants a sticky board that was placed
under a project hive's screened bottom board 48 hours prior to checking
back. The board is now ready for counting the number of Varroa mites that
have dropped onto it. To calculate the Natural Drop (ND), the number of days is divided into the number of hours to establish the daily mite count ( eg. 48 hours = 2 days, so if 10 mites were counted, then it works out to 5 per
day.)