Slug (IMAGE) Penn State Caption Slugs were unaffected by neonicotinoid insecticides, likely because they are mollusks and not insects, but they did pass the insecticides to their predators. Credit Margaret Douglas, Penn State Usage Restrictions non commercial use only 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.