Jim You understood me only partially. Re: "Glad to hear they die relatively quickly when out of the hive." Let me clarify---off of bees they will die relatively quickly. On flying bees out of the hive, they will enjoy free rides to possibly infest another hive. If infested larva are thrown out of the hive, the mites on them will probably continue their development and theoretically, if another bee sits down, it could be a source of infestation. All infested brood thrown out of the hive should be squashed--that puts a quick end to the mites' development.