Basically:

"Ants built a mound near a hole, some started falling down and couldn't get back up; with no food, lower ants had to eat ant corpses; the lower ants also built a mound (with no pupas) and dragged corpses that have been eaten onto a pile; later scientists removed the obstacle so that ants that fall down could get back up".

I'm a bit disappointed that the "soviet nuclear bunker" didn't play a bigger role.