I'm platinum level so I don't think I have enough micro to split units when I see a mine about to fire.
In early game, I tried zerglings & roachs, speedlings seem to be the best for me because I can send some suicides to deactivate alone mines, then progressively go forward.
But since there are marines with mines, I can often barely trigger the later. I tried to provoke friendly fire but this occurred not to worth the change for me (after comparing losses on replay).
Mine drops are not really a problem for me if (when I'm well aware), now I simply do at least a spore and a spine on each mineral line, and pull off my drones when the drop is coming.
In late game, I dispatch overseers then some lings when I see mines, but I still break my teeth on defenses with mines.
So the question is:
In zerg platinum level, how to counter widow mines in early, middle, late game ?