Frog Hops (video) Brown University Loading video... Caption To see the best bullfrog hops, scientists traveled to Calaveras County Jumping Frog Jubilee. Credit Michael Cohea/Brown University Usage Restrictions Available for use with credit. 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.