It is commonly thought that rodents are functionally blind when their surroundings are illuminated with light of longer wavelengths, which humans perceive as red. A new study, published in eLife by Nader Nikbakht of the Massachusetts Institute of Technology and Mathew Diamond of SISSA—Scuola Internazionale Superiore di Studi Avanzati—challenges this assumption and shows that rats can accurately discriminate objects that are illuminated only by red light. "This result demonstrates that rodents have very good visual form perception even under conditions of weak activation of retinal photoreceptors. The findings have implications for the design of experiments and the housing of rodents," Mathew Diamond, Director of SISSA Tactile Perception and Learning Lab says.