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In this outdoor activity, learners find the swollen bumps known as "galls" on various plants and get a closeup look at the parasitic animals living inside. Galls form on various plants including rosebushes, oaks, elms and willows after a female insect places one or more eggs into the living tissue of a branch or leaf. Learners explore what the galls provide, such as food or protection, as eggs become larvae, and what effects larvae have on their specific host plants.

Quick Guide

Learning Time:
45 to 60 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 8 - 18

Resource Type:


Materials List (per group of students)

  • strips of bright cloth or plastic flagging
  • bug boxes or hand lenses
  • plastic bags
  • 1 or 2 sharp knives
  • 3 or 4 pairs of tweezers
  • data board or large drawing pad
  • felt pen


  • Life Sciences
    • Diversity of Life
      • Plants
      • Animals
    • Ecology
      • Ecosystems

Informal Categories

  • Animals
  • Nature and Environment
  • Outdoor Activity


To use this activity, learners need to:

  • see
  • be mobile
  • touch

Learning styles supported:

  • Involves teamwork and communication skills
  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access



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