True. Bees don’t usually fly more than 3 miles from their nests and must have a constant water source. So watching the direction they fly when leaving the nest can be a valuable tool for locating water. Flies stay even closer to water – about 100m or so. Paying attention to insects and vegetation can be very important to finding water. According to The Backyard Beekeeper by Kim Flottum, bees seek water sources that are scented. They smell the water and they fly to it. That’s why you see bees at swimming pools or stagnant puddles vs. fresh water sources. Once they find a source they mark it with a pheromone so the other bees in the hive will find it. My grandfather could locate a wild bee hive by sitting in a field of flowers and watching which direction the bees flew when they left. He would then walk that direction and repeat the process until he pin pointed the hive. Seems reasonable that you could do the same thing for water.
The exception to this might be flies in the desert. Those little buggers seem to come out of nowhere. Not a drop of water for miles but the flies still seem to survive.