Scientists looked 1,640ft below North America's Great Lakes - and found a hidden world of predators, prey and parasites

It’s a well-known fact that the ground beneath us is bursting with life – at least in the first few metres of topsoil where bugs, microbes and fungi thrive. But hundreds of feet below the surface, scientists long believed there was very little. It was thought these dark, rocky depths were too extreme for most forms of life. Now, that idea has changed.