Raccoon, Asian tiger mosquito, or grey squirrel: Invasive species cause damage worth billions, destroy crops, or transmit deadly diseases. And this is becoming an increasing problem. According to a study published in the journal Global Change Biology, the number of species migrating to new areas is expected to rise by 36% between 2005 and 2050.

But do foreign and invasive species always cause destruction? Or are there some that actually benefit us and our environment?

A film about current controversies and the search for the right perspective.