ectotherms (IMAGE) Penn State Caption he study results may explain a phenomenon that scientists have witnessed associated with invasive forest plants, researchers say. They may explain why temperature sensitive species such as butterflies, bees and amphibians are not found in invaded understories in the same numbers that they are in uninvaded understories. Credit Erynn Maynard-Bean/Penn State Usage Restrictions non commercial use only 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.