Charcoal and ashes?

[Bob7777777777]

Recently saw great numbers of Common Blues (I think) sitting on extinguished campfires in a nature reserve in Europe. Presumably they're after a mineral in the charcoal? Or is it that the blackness attracts heat? No other butterflies nearby seemed to care. I suppose it could be mud puddling if charcoal retains moisture after rain but it was a very hot day and I don't think there would have been any dampness left. Does anyone know more about what this is all about?

[David M]

The interesting thing from a personal perspective is that Common Blue is a butterfly that I have never seen 'puddling' in my many trips to France. Perhaps the normal trickles of water onto tracks don't have the minerals they seek yet charcoal does?