Spiny Water Flea (image) University of Wisconsin-Madison Share Print E-Mail Caption Spiny water fleas are a type of zooplankton that travel in swarms and are pushed around by wind and currents. They are present in the greatest numbers in Lake Mendota in the fall. Credit Jake Walsh Usage Restrictions None 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.