Spay and neuter services can reduce the number of feral and free-roaming cats, but the invasive procedures are expensive and require a high level of veterinary training. Researchers have considered an injectable contraceptive vaccine—GonaCon—that has been shown to be effective in several mammals, including deer, horses, and laboratory-raised cats. But field-testing such a product is complicated. That’s why a group of University of Illinois researchers created a unique study environment designed to bridge the gap between the lab and the real world. In short, it’s a cat wonderland in which resident cats help to advance science.