I too have wondered at the bees interest in "dirty water." For many years I kept bees next to my horse barn and... especially in the spring (there may be something to that)... the bees would seem to have a great interest in the thawing manure pile. I assumed they were acquiring water, but less tasty water was available. Perhaps in the spring there is a need in the hive for minerals not needed during other seasons. Larry Krengel Marengo, IL