From caffeinated spiders to glow-in-the-dark beagles, animal experiments have taken a number of unusual forms. Some have been blatantly unethical, others just eccentric, but all of them required a fair bit of creativity from the scientists. In the slideshow below, you'll find nine of the most fascinating experiments from science history. You'll get the "aww" -factor of the monkey's with prosthetic arms, along with the fierce controversy over Dr. Harry Harlow's sensory deprivation experiments. We'll let you decide where they all stand, ethically speaking.
Animal Experiment You Won't Believe