Bees love and need salt. They will seek animal urine and manure piles at the ends of barns, etc. if is not provided for them.
Feel free to put some salt into their drinking water. (You all have a water set up for your girls, right?)
One should provide running water for bees. If you don't, they will find it on their own. Most likely in the neighbours swimming pool.
Stagnant water, pool water, is not good cause it is a breeding ground/water for various diseases, mainly nosema.
One can open the outside garden tap, just a tad and let water drip on a slanted board with hatched grooves or tacked on cleats.
A barrel of some kind is best, with affixed tap so water is dripping on slanted board or mossy rock and pea gravel.
Give them about two grams of table or sea salt, to each gallon of water. About one fifth of teaspoon.
Salt is useful to bees.
In Europe they use it manly in spring. They say it prevents the May-disease?
Too much salt is harmful to the bees. It is said, that it shortens their life span. . . .