We've lent this to a fellow beekeeper two years in a row now. I'm wondering if this year he'll build one of his own. I doubt it, but now would be a good time since Labor Day is "traditionally" when we Coloradans harvest our honey.It's an "escape board," a chemical-free way to clear a super of bees overnight. In the afternoon when most foragers are still out in the field, the escape is inserted below one or more supers, maze facing downward. In the evening when it's time to rejoin the cluster, the bees go down the hole and encounter the maze. The tunnels guide them out in a fairly organized stream, but if the super is really full of bees, it may take two evenings to clear it of bees.
After successfully navigating the maze, they generally don't try to do it backwards. However, if you leave the escape board on long enough, they will figure out how to get to their honey and you'll be greeted with stingers when you pull your supers off. And that's why my friend the procrastinator probably won't be making one of these. If you're interested in building one, here are the plans. http://www.dave-cushman.net/bee/vortexescape.html
If you're interested in seeing how we used this on our Top Bar Hive, then this is the post for you: The Great Escape