When I set up the bird bath, I wasn't thinking of the bees. There is water in my neighborhood - a nearby creek and feeder streams all over - so plenty of water available. But the first warm day this winter, I noticed bees in my bird bath, struggling to maintain their footing and a couple of dead bees in the water. I immediately added wine corks. Only a couple. I want the birds to use the water AND I wanted to accommodate the bees.
I noticed a very interesting feature of the corks when I was watching the bees in the bird bath yesterday. You'll see too when you look closely at this photo:
Look at the unfocused bee on the cork. Her proboscis is stuck down in the cork. She is using the porous cork to suck up water absorbed into it, rather than risk drowning by balancing her way down to the surface of the water.
Even with the cork, there are bees who drown, but it at least provides a modicum of safety for those searching for water. The bees floating in the water are dead. But the ones on the back cork in the first photo look like they are winning the bee log-rolling contest. They are actually getting water between the two corks which don't move because the ice in the bird bath has glued them together.
