Give each learner or group a caterpillar head template to start with After each thinking step, learners add a body circle describing what they did and why The caterpillar "grows" as thinking progresses through the lesson At the end, learners review their caterpillar to articulate their full thinking journey

Caterpillar - Visual Thinking Journey

How it works

The caterpillar is a visual representation of a learner's thinking journey. Each circle of the caterpillar's body represents a significant step in the thinking process. Learners start with just the head and add body segments as their thinking develops through a lesson or across several lessons.

Inside each circle, learners record what they did and why, using agreed thinking vocabulary. They might write "We asked questions about the picture" in one circle and "We compared our ideas with another group and changed our minds" in the next. Pictures can be used alongside or instead of words for younger learners.

The power of the caterpillar is that it makes thinking visible. A learner must articulate to another person why their caterpillar has "grown", explaining the steps they took and the decisions they made. This is metacognition in action. Learners are not just doing the task but thinking about how they are thinking.

It can be used on a whole-class basis (a large caterpillar on the wall), in groups, in pairs, or individually. It works for a single lesson or can track thinking across a whole unit of work.

Classroom example

Year 3 learners in a Ceredigion primary school are studying shapes in Mathematics and Numeracy. Working in groups of four, they have a 'feely bag' containing objects and ten picture cards of shapes. One learner is the 'tester' who feels an object in the bag. Others ask yes/no questions using shape vocabulary. Each round of questioning becomes a caterpillar segment: "We asked about corners", "We asked about curved edges", "We decided it was a cylinder." By the end, each group's caterpillar has six or seven segments showing their classification thinking process.

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Curriculum for Wales connection

The caterpillar directly develops the "Reflect" strand of thinking skills, specifically metacognition and unpacking the thinking process. It makes the invisible visible, which is exactly what the Curriculum for Wales asks schools to do with developing thinking.

Rainbow Curriculum's Thinking Tools lens lets you map where metacognitive tools like the caterpillar appear in your curriculum, helping you build progression in reflective thinking from Foundation Phase through to Key Stage 3.

Tips

Use agreed thinking vocabulary on a classroom display so learners can draw on it when labelling their caterpillar segments.
Start with just the head and the first circle. Do not introduce all the segments at once.
Photograph completed caterpillars. They make excellent evidence of thinking for Estyn and for learner portfolios.
A common pitfall: learners describing what they did rather than how they thought. Model the difference explicitly.
For younger learners, use pictures and simple sentence starters inside each circle.

Related tools

Graphic Organiser to Monitor Progress

A flexible flowchart where learners plan their approach, track what they actually do, and annotate changes along the way, making their thinking process visible.

Learning Logs

A structured record where learners regularly reflect on what they have learned, how they learned it, and what they need to work on next.

Reflection Triangles

A visual self-assessment tool where learners rate their understanding, effort, or progress on three dimensions, plotting their position on a triangular diagram to create a balanced reflection.

Triangles

A quick self-assessment tool where learners shade sections of a triangle to indicate their understanding of three related learning objectives, creating a visual snapshot of their progress.

Caterpillar

What is caterpillar?