Strange drone caps of Apis cerana. Workers remove the wax a few days after the drone larvae were sealed, exposing the cocoon-cap which has a small hole on it. The signicance of the hole is not clear. However, we do know the strong capping can only be opened by the drone when he emerges. Workers outside cannot open the caps, leaving dead drones to mummify inside. This can be another mechanism of mite-resistance because if the drone pupae has too many mites and dies, mites will be trapped inside and will also die.