Sophia Learning
Sophia: Essential Elements: Lesson 2
This lesson will introduce the 4 elements that make up most of the body: Oxygen, Nitrogen, Carbon, and Hydrogen. It is 2 of 4 in the series titled "Essential Elements."
BBC
Bbc: Nature Wildfacts: Common Earthworm
Before you go looking for an earthworm, learn more about it from this detailed fact sheet and from these close-up photos.