Think I learned something about a bees. You hang sugar water to feed them when there are fewer flowers for them to feed on?

A couple years ago I recall the strange phenomenon of finding dozens of bees spending their dying breaths drinking rancid water runoff made by my fresh compost. By the end of the day, they would be drowning in it. I am guessing the sugar content of the rotten fruit is so valuable to a famished bee, that is why bees swarm to it in the late season. Is this something you have knowledge about?