Crayfish Urine Fight (IMAGE) BMC (BioMed Central) Caption Two crayfish fight in a cloud of visualized urine. Credit Fiona Berry Usage Restrictions Please credit Fiona Berry; BMC Biology 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.