Save the bats
The white nose syndrome has already killed millions of bats over the past years in US and Canada. White nose is caused by a fungus - the evil Geomyces destructans - that prompts bats to wake from their winter hibernation and die after they fly into the cold air in a doomed search for insects. The syndrome spread threatens the survival of entire bat colonies and could push some species to extinction. Which, needless to say, would also screw up the entire ecosystem.
Compassionate souls can go to SaveOurBats.org.