Although worm bins have been used by K-12 and nonformal educators for decades, there is little evidence of their use in postsecondary education. The ease of use, maintenance, affordability, portability, and diversity of scientific concepts that can be demonstrated with a worm bin make it a valuable tool in college science classrooms. The purpose of this article is to report on the use of worm bins in introductory environmental science classes to demonstrate and promote discussion about the biological processes environmental benefits of composting. It also describes adaptations for using the worm bin in other science courses. (Contains 2 figures and 1 table.)