Oyster Drilled (image) University of California - Davis Share Print E-Mail Caption This native oyster from Tomales Bay, California, has survived four drilling attempts by oyster drills, a predatory snail. Credit Brian Cheng/UC Davis Usage Restrictions Provide Credit. 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.