Then one morning, the scientists checked their experiment and found one of the little guys chirping like a bird.
Although the singing mutation is random, it appears that the mice are actually using it to express themselves. Male mice sing more often around female mice, presumably to attract them as mates. The mice also sing more when they're placed in different environments.
And when they're looking for Fievel Mousekewitz.
The researchers also claim that the singing mice may help us understand the origins of human speech, noting that the mutated mice seem to be developing different dialects depending on their environment.
Lead researcher Arikuni Uchimura had this to say about the project: "I know it's a long shot and people would say it's 'too absurd'... but I'm doing this with hopes of making a Mickey Mouse someday."
And maybe, one dark day, a SpongeBob.