During my afternoon stroll at a nearby park I noticed a good many bees buzzing around this tree. My first thought was that perhaps there was an active hive inside. Upon closer inspection, I found instead that they were busy slurping up sap from holes in the trunk.
I presume the holes were drilled by a very efficient sapsucker, though I did not see one in the vicinity. Ever curious, I tried the fluid myself. I was not impressed by it, not surprisingly, it was primarily a tannic flavor.