Nettle (IMAGE) Technical University of Denmark Caption A new study explains for the very first time the principles behind the design of stings, needles, and spikes in animals and plants. The principles can be directly used in the development of new tools and medical equipment. Credit Kaare Hartvig Jensen Usage Restrictions Credit Kaare Harvig Jensen 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.