Shannon M. Gaukler, University of Utah (IMAGE) University of Utah Caption A University of Utah test detects hidden toxic effects by subjecting mice to competition for resources. University of Utah biologist Shannon M. Gaukler, lead study author, stands in front of the test enclosure, illuminated in red light that mice perceive as nightfall. Credit Andy Brimhall / University of Utah Usage Restrictions None License Licensed 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.