This resource has several lessons consisting of short, on grade level readings, followed by questions. I would not use this in entirety but could see me pulling out Lesson 3-1 (What is a Beneficial Insect?), Lesson 3-2 (Predators), Lesson 3-3 (Pollinators) and Lesson 3-4 (Recyclers and Decomposers).
Students make "birds" by using straws and paper strips. By the flip of a coin, the "bird" mutates and is tested to see if the mutation is beneficial or not.