It's furry like a mouse but sings like a bird. What is it? It's a mutant mouse developed by the genetic engineers at the University of Osaka that is able to tweet and chip like a bird, instead of a mouse's normal squeak. Like dog breeders, who actively select for certain traits (like size, hair color, or disposition) the researchers from the Evolved Mouse Project crossbred their mutant mice to select for various traits. When they find one they like, like this singing mouse or the one that looks like a miniature Dachshund, they breed them until they have a sizable breeding stock of animals to establish a new breed. The research group currently has over a hundred singing mice (it must get noisy in those labs) and they are continuing to study how they use their chirps, researcher Arikuni Uchimura told the AFP: