May I reiterate about the DSBB and oil pan. I had not felt like servicing the oil pan, for several months, and I had lots of SHB a couple of weeks ago. I saw lots of SHB in the semi dry oil pan so I poured used cooking oil, from a fish fry, in the pan, without cleaning so that I killed all of the SHB. I checked a few hives most were double deeps, the first of this week. The only SHB I saw were in the oil. This works, but if I worked as many hives as I have, in my younger days, I am sure this would be more trouble than it is worth. BUT, I believe that one hive with oil pan in 5 to 10 hives would work almost as well, especially if some pollen pads or slime out bait were placed in the oil pan. I can service my oil pans from the rear of the hive with no smoke or hood. No bees can get in the oil pan unless a coon opens the door to the oil pan compartment, yes this has happened, with lots of bees in the oil. To service the oil pan I use a 5 gallon bucket and a strainer to strain out any SHB and debris, then the oil is recycled. If the hive is level only 1/2 inch of oil is necessary. I like to use water with a wetting agent added either Dawn or calgon or the active ingredient in Calgon. I buy in 5 pound sacks or larger. I also use this in the RV toilet, The active ingredient is Sodium hexa meta phosphate, available in small quantiles in the internet, or better from a chemical supply. With SHMP added to water any insect sinks as there is very little surface tension, this also kills mosquito larva, and is safe for human consumption as it is found in many blended syrups and sauces. The reason I don't use water is that it evaporates very quickly in our Texas 100+ days, especially if SHMP is used, oh yes it is used in steam boilers and water distillation units as well as commercial Reverse Osmosis units.