Rats, by and large, aren't terribly popular animals. But while you don't want an infestation of common black rats living in your house, their distant cousins in the Philippines are downright cuddly. These "giant cloud rats" live in the treetops of misty mountain forests, and they fill an ecological role occupied by squirrels in the US. And, it turns out, we have new evidence that they've been living in the Philippines for a long time—scientists have discovered the fossils of three new species of giant cloud rats that lived alongside ancient humans.