When I was younger I used to do at least 50 bee removals every year. This involved removing bees from walls and ceilings mostly. These days I mainly just collect swarms. When we remove wild bee nests there is normally a lot of bee brood.
Drone brood is very easy to see – the cells are larger than worker cells, and the capped brood bulges out like a half peanut from the frames. Worker brood has an orange fluffy capping and drone brood is even more fluffy.