Lesson 3

4-H Vermicomposting
A 5th grade school enrichment
Lesson 3: Earthworm Anatomy
• Objectives
– Learn and discuss internal and external
anatomy of worms
– Discover some characteristics of worms
• Review
– Why are earthworms important
– Describe the set-up of a worm bin
Did you know?
• Worms have no eyes
and are sensitive to
• Worms have no lungs
or gills and breathe
through their skin
• A worm’s skin needs to
be moist to breathe, so
bedding must be moist
They do not
wear glasses
External Anatomy of a Worm
(1) Anus—where waste is excreted from worm
(2) Segments—areas of worm’s outer body that bend, stretch and aid in
(3) Setae—stiff hairs on exterior of worm that help it move
(4) Clitellum—located near worm’s head; genitalia is located here
(5) Mouth—where worm ingests food
Earthworms’ Internal Organs
Is an earthworm a vertebrate (an animal with a
backbone) or an invertebrate (has no backbone)?
Worm Cocoons
•Worms cocoons
contain an
average of 3 baby
•Cocoons are
shaped like
lemons 1/8 of an
inch long
Questions to Answer While
Examining Your Worm:
(1) How does worm feel and react to touch?
(2) How can you tell which end is the head or tail?
(3) How does the worm move?
(4) Does the worm have an odor?
(5) What color is the worm? Does it have markings?
(6) Can you see through the skin? What do you see?
(7) Does the worm have a swollen band around it?
If so, what is it called?