Iain Couzin: Lessons from a Cannibal Plague

Iain Couzin: Lessons from a Cannibal Plague

National Geographic Emerging Explorer Iain Couzin shares lessons about decision-making from a cannibalistic locust plague.


5 - 12


Biology, Geography

NG Live

This video was filmed on Wednesday, June 13th at the 2012 National Geographic Explorers Symposium at National Geographic Society headquarters in Washington, D.C., United States.


National Geographic Emerging Explorer and behavioral ecologist Iain Couzin shares lessons from a cannibalistic locust plague. Whether looking at what causes locusts to swarm, or how people function as a society, Couzin is finding fascinating ways to explain how organisms accomplish things in groups that they never could as individuals.


  • Why do locusts undergo mass migrations? (start-2:04 min.)
  • A cannibalistic discovery: studying locust hopper bands with motion-tracking software (2:05-3:15 min.)
  • A perilous field study in Mauritania (3:16-5:08 min.)
  • Another cannibalistic discovery: reviewing data from the Mauritania field study (5:09-6:35 min.)
  • Why locusts and crickets swarm (6:36-7:10 min.)
  • How non-cannibalistic animals make group decisions (7:11-10:08 min.)
  • The influence of networks, opinions, and non-informed individuals (10:09-13:38 min.)
  • Using fish to test a prediction about group decision making (13:39-15:31 min.)
  • Future studies: contagious behavior (15:32-16:29 min.)

Strategies for Using Video in a Variety of Learning Environments

  • Have students preview several of the videos and choose the one they find most inspiring. Have students describe in writing a conversation they might have with the speaker(s).
  • Freeze the video on a relevant image. Have students observe details in the still image and jot down predictions of what the full video might address. Discuss students’ ideas before and after watching the video.
  • Pose an open-ended question before students watch the video, and have them discuss their ideas before and after in small groups.
  • Have students determine what they think the key message of this video is. Was the speaker effective in getting his or her message across?
  • Show a short clip to engage students during class, and then have students watch the full video at home and write a paragraph responding to the content or a question you give them.
  • Have students note statements that represent facts or opinions, including where it’s difficult to tell the difference. What further research might help distinguish facts vs. opinions? How might the speaker’s viewpoint compare with others’ viewpoints about a topic?
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Page Producers
Nina Page, National Geographic Society
Samantha Zuhlke, National Geographic Society
Last Updated

October 19, 2022

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