Juliet Tuttle may have been the most prolific murderer of pets in American history. How did she get away with it?

As humans drive vulnerable mammals closer to extinction, valuable mutations hidden in their DNA could be bred out of existence.

What appears to be a life-affirming triumph is really a cautionary tale about drones and wildlife.

Pets left behind when people fled the disaster in 1986 seem to have seeded a unique population.

The threat to humans is low. But the status quo is still pretty troubling.

New evidence is prompting some researchers to rethink ethics in the lab.