Glow-in-the-dark monkeys: Totally cool, totally useless, or both? Japanese scientists have engineered monkeys that glow under UV light. They also pass the trait onto their offspring, a breakthrough that will aid research to cure diseases such as Parkinson's, the BBC reports. Exactly how glow in the dark monkeys help scientists—beyond finding them if the lights go out, of course—remains unclear. Not surprisingly, some animal rights groups are uncomfortable with the modified marmosets. One critic insisted that monkey's brains actually are not very useful for scientists seeking cures to human ailments. Another scientist, conceding that the glow-in-the-dark monkeys served no obvious purpose, remained thrilled. "This experiment is reminiscent of the exciting early days of transgenic research where it was initially difficult to fully know what the potential applications and future research directions might be," the scientists said. To which we respond: Jungle-themed rave party.