Efforts to promote and develop new forms of sustainable energy have pushed wind power to the forefront. However, this type of power comes with a cost – as it often interferes with birds’ and bats’ migration, killing hundreds of thousands of these winged species. According to a new study from the University of Colorado Denver, more than 600,000 bats were killed by wind energy turbines in 2012. This has serious environmental repercussions as bats help pollinate crops and help control harmful insect pests.