I am wondering if anyone on the forum has had any experience on the topic. I placed this on some of my hives exactly one week ago today. I talked with a commercial keep in the area who was also using the same product so we shared some thoughts. One of the things we noticed was under the faq's section. A recommendation to help prevent bearding out side the hive was to place an empty super on top of the double deep brood chambers which would allow the bees to move away from the initial strong vapours. Both of us did. Neither the commercial or myself noticed any bearding (well, maybe one in my collection). Now we are hearing that some keeps in Ontario are experiencing queen failure. I also got a call from a fellow keep in our old town (Lunenburg) that has 4 hives and noticed a high bee kill in front of all 4 of his hives. I asked whether he added the super and he had not (it is not mentioned in the instructions). I hope to go through some of my hives middle of this next week to see if there was any issue with queen failure. I figure if I see eggs or even larvae I should be able to relieve any fears. The commercial is waiting to hear from me as well.