Try, Try, Again.

The next visit revealed that it wasn't necessarily the case that the bees died because of the slope of the tube. On my next return, the tube was once again plugged with dead bees. Unsure of what the issue might be, I cut off about 8 inches of the tube to clear the obstruction and shorten the run from the wall to the box.

Once this was accomplished, I watched the bees in action for a bit and observed that they would crawl out as far as possible from the wall but did not seem inclined to follow it as it turned into the box. Instead, they would flail at the side wall trying to escape to the sky so clearly visible. Apparently the lure of the wide open blue was blinding them to finding the route that would actually set them free.

Capitulating to the realization that I had presented too complex a puzzle for them to solve in one step, I located some opaque flex tubing (from an old hand held vacuum) and cut enough to cover much of the clear tubing. This was threaded over the clear, leaving only about four inches of clear tube visible right next to the wall. This modification seemed to improve things a bit - a few bees made the trip, but it was a cloudy, wet day and the bees were not very active. It may be that the route will have to be completely blacked out and perhaps exposed later after they have learned the way, but we will try this for now.