© Nicolas Mertens. All Rights Reserved.
Menorca: Alaior—Pine processionaries.
As I was taking this photo, a passerby told me that the length of such "processions" can reach several meters. Later, I read in Wikipedia that these are pretty nasty bugs. They destroy pine trees and they can cause severe allergic reactions in humans and other mammals.
More urticarial when viewed Large, on Black :)
This picture is geotagged. See the shooting location on the map.