Compost Critters
Fungus, Bacteria, Invertabrates
Place of Learning: 
Grade Level: 
In this lesson, students learn about the organisms that decompose organic matter.
Student Learning Goals & Objectives: 

Students will:

  • Add organic materials to the compost piles.
  • Identify living things in compost.
  • Identify the role insects play in maintaining healthy soil.
Materials & Prep: 
  • Buckets of amended soil and non-amended soil
  • Magnifying lens for looking more closely
  • Compost Criters Worksheet – PDF


Procedure Steps: 
Activity Preparation
  1. Prepare containers of amended soil and non-amended soil samples (add rocks of different sizes, wood chips, plants, and some worms).
Digging for Compost
  1. Show the compost samples. Invite students to explore the samples using their senses.
  2. Discuss the different critters found in healthy soil.
    • Students shovel out scoops of compost from a bucket, pull out items they find and talk about why they are in soil and why they are important to soil.
  3. Ask:
    • What kind of critters did you find?
    • Why are insects so important to our compost? (Digest our left over food, water/air, burrows or tunnels, and mixing soil).
  4. Students use the worksheet, Compost Critters, to circle and color the critters they find. Some students need extra challenges to stay engaged. Ask these students to count the number of each critter they find.
Student Reflection
  1. What did you find in the soil that surprised you?
English Language Learning (ELL) Focus: Science Verbs
  • Sorting
  • Examining
Additional Information

Use grade appropriate descriptive vocabulary to invite students to use their senses to observe living things in compost, such as sticky, moist, moldy, fresh, etc. If students struggle to describe what they see, prompt them with examples.

Download Lesson Materials

Academic Standards

Next Generation Science Standards

Disciplinary Core Ideas


Natural Resources: Living things need water, air, and resources from the land, and they live in places that have the things they need. Humans use natural resources for everything they do

Science & Engineering Practices

Constructing and Designing Solutions

Constructing explanations and designing solutions in 6–8 builds on K–5 experiences and progresses to include constructing explanations and designing solutions supported by multiple sources of evidence consistent with scientific ideas, principles, and theories.

Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students’ own experiments) and the assumption that theories and laws that describe nature operate today as they did in the past and will continue to do so in the future. (MS-ESS2-2)

Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.

Apply scientific ideas or principles to design an object, system, process or tool.