Engaging students in hands-on inquiry helps them develop skills associated with the scientific process. Development of simple experiments using model caterpillars can provide an experiential demonstration of the scientific process and ecological principles for high school students. Caterpillar models are formed from plasticine, a nontoxic, nondrying modeling clay, and are an excellent tool for quantifying relative predation rates by birds, small mammals, and invertebrates. Lifelike surrogate larvae are glued to vegetation for short periods (one week) and retain identifiable marks (beak, teeth, mandible imprints) following predator attack. This technique is simple, inexpensive, and provides rapid and clear results, rendering it a highly effective method of inquiry for high school students. Students can use these methods to ask a variety of research questions, such as comparison of predation in nearby habitats (park vs. backyard), vegetation (tree vs. shrub), season (spring vs. fall), or coloration (aposematic vs. camouflage). For many students, this may be one of few opportunities at the high school level to investigate science “in the field” and integrate scientific practices, such as the scientific method and inquiry, in an authentic research experience. Participants develop their scientific reasoning skills through creation of research questions and interpretation of results. They learn experimental technique, build field skills, and work collaboratively. This experiment aligns with the Next Generation Science Standards.

Active-learning approaches can improve understanding of core biological concepts. We describe a revised hands-on simulation for teaching evolution by natural selection, which focuses on prey–predator coevolution in escape/pursuit speed. It illustrates how selection pressure on individual speed increases average population speed through differential survival, while also reducing variation in speed among individuals. A simulated beneficial mutation helps differentiate the generation of individual traits from the process of natural selection and illustrates the effects of a beneficial mutation on immediate and subsequent generations. Overall, this exercise addresses several common misconceptions and allows students to collect and assess their own data, quantitatively. We report results from pre- and post-assessments in an introductory, undergraduate biology class, which indicate significantly improved understanding associated with the simulation.

The term frequency dependence describes scenarios in which the likelihood of an event occurring is strongly tied to how common a particular trait is. Understanding frequency dependence is key to understanding numerous biological processes relevant to evolution by natural selection, such as predation, mimicry, disease, and effective vaccinations. We use dodgeball to demonstrate frequency dependent selection in a hypothetical predator–prey community, and provide possible extensions into other topics. This activity can be used with biology students in high school through upper-level undergraduate courses.

Optimal foraging theory explains that organisms whose foraging is as energetically efficient as possible should be favored by natural selection. However, many individuals must exhibit trade-offs between foraging and other factors in their environment (i.e., predation risk, competitive interactions). We present a hands-on activity for undergraduates using just a deck of cards, bingo chips, and dice to introduce ecological concepts of foraging theory, predator–prey interactions, and energy trade-offs. Specifically, this activity will focus on optimal foraging theory and giving-up density. Students should gain an understanding of how organisms balance predation risk and competitive interactions with energetic demands. Further, this activity can be scaled for nonmajors and introductory courses to introduce general ecological concepts, or for upper-division courses to explore advanced topics in foraging theory.

Predator–prey dynamics are an important concept in ecology, often serving as an introduction to the field of community ecology. However, these dynamics are difficult for students to observe directly. We describe a methodology that employs model caterpillars made of clay to estimate rates of predator attack on a prey species. This approach can be implemented as a field laboratory in almost any natural or seminatural setting, and is designed to allow educators to pursue any number of student-generated hypotheses representing varying degrees of scientific sophistication ranging from middle school to college level.

I present a framework for ecology and evolution laboratory exercises using artificial caterpillars made from modeling clay. Students generate and test hypotheses about predation rates on caterpillars that differ in appearance or “behavior” to understand how natural selection by predators shapes distribution and physical characteristics of organisms.