Wet Marbles…

…who needs 'em?
    There was an item, recently, on Farcebook/Fakebook advising a shallow Saucer/tray/similar, with a layer of Marbles/Pebbles in water to give Bees, etc. somewhere to drink.
    My comment?  Who needs Marbles, with a Pond full of Duckweed? I spotted him/her while I was hauling another few kg of Water Forget-me-not out for composting.