These stingless bees have made their nest inside a termite mound. Earlier in the day, the bees weren’t clustered around the entrance like they are here. Instead they were simply flying in and out occasionally. This was taken late in the day though, and I suspect they are preparing to seal the entrance for the night. In the photo below, you get a better sense of how the nest is situated in the termite mound.
Though these bees are stingless, they aren’t defenseless. Do you see the clump of resin in the upper left? Looks like an ant has been encased there. I wonder if the bees perhaps mobbed it and secreted all that resin.
One of the common names for these bees in Brazil is torce-cabelo, which means hair-twister. I once got a little too close to a nest for the bees’ comfort. In return they made me quite uncomfortable. At first I didn’t realize what was happening. Suddenly they were crawling all over me, getting tangled up in the hair on my head, my arms, and anywhere they could grab hold. Having experienced that, I’m not likely to forget their common name.