Wood bugs: close observation

Students closely observe wood bugs and their body parts, and learn about their life as a crustacean on land.
Science content
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Classification of Living Things, Biodiversity (1, 3)
Biology: Food Webs, Ecosystems, Biomes (3, 4)
Biology: Sensing, Organ Systems (4, 5, 6)
  • wood bugs, one per student
  • either: small petri dish lined with dampened paper towel for each wood bug, and a magnifier, for each student
  • or: box magnifiers lined with dampened paper towel for each wood bug, for each student

Set-up prior to experiment: a box magnifier or small clear dish, the bottom lined with damp tissue and containing a live wood bug, for each student.
For biomes lesson, keep wood bugs in their habitat, and provide magnifiers.

If using them, show students how to use magnifiers.

Keeping the wood bug sealed in the container, students look at them closely, and draw what they see (not what they think they should see). Sometimes they will see a feature that they don't know what it is, but that is OK.
Class discussion, led by what students notice. Points to include: colour, body parts of wood bugs, and how each of these might help the wood bugs survive.

Wood bug information:
They are a colour that makes them well camouflaged in the dark brown and grey places they are often found. Wood bugs have 14 legs - they are crustaceans. Wood bugs have antennae for feeling around and smelling. They have an exoskeleton to protect them, which is segmented. Only some wood bug species are able to roll into a ball. Wood bugs are closely related to (and evolved from) ocean-living crustaceans such as shrimp (thought to have colonised land in the Carboniferous period). Like the ocean animals they are related to, they have gills - using them to extract oxygen from water (the gills are the flat white structures underneath near the tail). Because of this, they always need to be in a moist environment, and will die fast if they dry out. They are decomposers, an important animal in food chains, eating dead plant and animal matter and turning it into soil.
More info:
Video about pillbug evolution from ocean crustaceans: also at

Sometimes the eggs under the female can even be seen.

For my lessons, I believe I found wood bugs from these three families: Armadillidiidae (pill bugs, which roll into a ball), Oniscidae and Porcellionidae. Reference: General information on wood bugs, including photos.

Wood bug images (including babies) in this article:
Wood bug moulting images:…

wood bug: a familiar animal with 14 legs and a hard exoskeleton; a crustacean that lives on land
crustacean: a large group of animals, segmented with an exoskeleton, mostly aquatic (e.g. shrimp, crab)
exoskeleton: an outer protective shell, found on animals that do not have bones
antennae: feelers at the front of the body, used for feeling and smelling surroundings
habitat: a place for a living thing to live

Attached documents
Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5