Hinako Katsushima and Takashi Hayakawa (IMAGE) Hokkaido University Caption Hinako Katsushima (left), first author, and Takashi Hayakawa (right), corresponding author of the study. (Photo: Takashi Hayakawa) Credit Takashi Hayakawa Usage Restrictions This image is copyrighted, and may be used to report on this press release as long as the copyright holder is credited. License Original content 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.