In this activity, you will explore how competition affects where organisms live and how well they survive. You will begin by watching a short video that introduces barnacles, their habitat in the intertidal zone, and the concept of competition between species. Then, you will work through an online interactive simulation based on real ecological research to see how two species of barnacles compete for space on rocks along the shoreline. By the end of this worksheet, you will understand how competition and environmental conditions shape species distribution. Answer key included.