Summary
Hermit crabs must borrow empty snail shells for homes, and when a good one appears they line up to trade. Deep Look shows the surprising 'housing chain' where crabs swap shells so several get a better fit at once.
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All ages
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Teaching resources
Discussion questions
Talk about it
Hermit crabs need shells to survive and compete for them. Sometimes they form an orderly line and swap in sequence, so a single new shell helps many crabs upgrade -- competition and cooperation together.
- Why do hermit crabs need to find empty snail shells?
- How can one new shell end up helping several crabs?
- What happens when a resource every animal needs is in short supply?
Quick work-a-long
Vocabulary: resource, shell, compete, survive.
Try it: Line up shoeboxes of different sizes and 'trade up' as a group. Write how sharing in order helps more crabs get a home.