The Varroa mite is the main killer of bees. So far, the parasites have only been able to be fought using toxins or acids, which is not only unsuccessful, but also harms the bees. Beekeepers from all parts of Germany have formed a movement to push ahead a new possibility of combatting the mites using hot air. A fully automated bee sauna increases the temperature in the hive. That kills the harmful intruders but not the rightful residents. The software provided controls the device automatically and provides data for a worldwide citizens' field experiment.