Kaplan's Think like a scientist as you observe a real live earthworm (nightcrawler)! Kindergarten, first, and second graders will love this hands on science activity. The lesson can be scaffolded by having Kindergarteners first observe the earthworm with a scientific tool (magnifying lens) and then complete the observation sheet with or without teacher help. The older children do the same, except think more critically by comparing the earthworm to a human- did you know earthowrms have 5 hearts?