What I gathered from the video is that he taped the entrances shut at night when most of the bees were inside the hive. Any bees that happened to be outside of

What I gathered from the video is that he taped the entrances shut at night when most of the bees were inside the hive. Any bees that happened to be outside of the hive when he euthanized it would die eventually from hunger since they didn't have access to a hive anymore.