Hawkmoth Hovering at Flower (image) University of Arizona Share Print E-Mail Caption By sensing a gradient in humidity, a hawkmoth can tell whether an evening primrose flower contains nectar without having to land and probe it. Credit Robert A. Raguso/Cornell University Usage Restrictions This visual may only be used in conjunction with reporting/posting of this news release. Image/video credit must be included exactly as indicated. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.