One key advantage I have found in feeder bags over inverted bottles is less spillage. When the daily temperature differential is great, cool/cold in the morning, sunny warm day, the air inside the bottle/pail expands, pumping out syrup. This is the weather patter during Spring and Fall feeding. You can usally see it running out the entrance early in the morning. As the bottle become less full and the volume of air increases the amount of spilling also increases. One advantage to inside bottle/pail feeding is easier access by the bees as they can access and remain in the warmth of the hive. For the feeder bag they need to climb on top of the bag. It may not matter that much though. Spilling while preparing - zip lock bags when they spill, spill the bulk of the syrup. You want the zipper zipped all the way (as my mother used to tell me as a child)! I have no experience with glass bottles as the Boardman feeders I have constructed use 64 oz. plastic fruit juice bottles. Lastly, when removing the bottle/pail can easily be removed partially filled without making a mess. With feeder bags you need to wait until empty. However, the bags can be lifted and replaced carefully if they are on a queen excluder or feeder bag tray of some kind, thus permitting hive inspections and manipulations. A steady hand is required though. --------------- I've been toying with an idea for emergency cold weather feeding and would appreciate comments. Since the feeder bag does not have spilling problem due to warming the following idea occurred to me. Basically a solar heated cold frame type stucture placed on top of the hive with the feeder bag and air space warmed by the sun during the day. The temperature permitting bees access. The design would be simple (like a solar wax melter) with the glass facing the sun. The design would need to keep the temperature from getting to high with vents or single pane of glass. _ | \ | \ sun | \ | \ | \ |__FB__| | | | hive | |------| | | | | -------- FB feeder bag(s). ------------------- Would the cluster disperse and find the syrup? Would the bees be faked into thinking it was warm outside? If so, I think I would need to confine the bees to avoid losses due to freezing. Would the then warmed and confined bees "have to go" thus soiling the hive? This is intended as an emergency feeding method only. I appreciate that the best way to answer the above questions is to experiment and a some point I will. Maybe someone on the list will give it a try. As a warning, I think the biggest risk would be to much heat, causing damage to the bees and comb if the cold frame is too efficient. Comments would be appreciated. Jim Moore [log in to unmask]