On hot summer nights we get flocks of ants that have grown wings (from what I know to migrate nests).
It appears the wings are not permanent, but are grown for a temporary purpose.
From what I know these events are triggered by climatic conditions (warm evenings).
In other species, wings seem like a really big deal and are grown from birth - wheras ants seem to just grow them 'on the spur of the moment'.
My question is How do ants spontaneously grow wings? Are they a spare layer of skin that is normally discarded and only comes into action when necessary?