Clam boreholes (IMAGE) Field Museum Caption Boreholes dug by the wood-boring clams. The clams fill these boreholes with their own poop, making the sunken wood an inhospitable environment for other species. Credit Meg Daly Usage Restrictions Please include credit License Original 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.