My husband spotted these two Swallowtail butterflies during one of our walks at the cottage. They were obviously very distracted because they let us get very close, but I couldn’t figure out what it was they were doing on the ground.
Then yesterday I was reading this Yellow Summer Colours Week post and it was all explained, with photos of four or more Swallowtails on a beach together. It is called a puddle club, in which they gather around puddles and damp areas that are rich in mineral deposits. Thanks, Margie!