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Two routes from a young insect to an adult

A caterpillar and a butterfly look like two completely different animals, while a young grasshopper looks like a miniature, wingless version of its parents. Insects take two distinct developmental routes to adulthood: complete metamorphosis rebuilds the body inside a pupa stage, whereas incomplete metamorphosis grows through a series of molts without one.

3–5 min

Questions you could explore

  • What changes between a nymph and an adult?
  • Why should the stage sequence not be taken as a rule about every species' diet or habitat?

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Nature and biology

How does a honey bee dance give directions?

A returning honey bee can communicate about food without leading every other bee to it. The direction and duration of its waggle dance carry information that other bees can use beyond the dark hive.

3–5 min

How does a honey bee dance give directions?

Nature and biology3–5 minA returning honey bee can communicate about food without leading every other bee to it. The direction and duration of its waggle dance carry information that other bees can use beyond the dark hive.

Nature and biology

How can an octopus change color so quickly?

An octopus can alter the appearance of its skin far faster than a new coat of pigment could grow. Tiny structures already in the skin control what becomes visible, with pigment and reflected light playing different roles.

5–7 min

How can an octopus change color so quickly?

Nature and biology5–7 minAn octopus can alter the appearance of its skin far faster than a new coat of pigment could grow. Tiny structures already in the skin control what becomes visible, with pigment and reflected light playing different roles.

Nature and biology

Finding prey through returning echoes

An echolocating bat uses the delay and character of returning sound to follow a target. Its calls can change as it approaches prey, connecting the sound it sends with the information it needs next.

3–5 min

Finding prey through returning echoes

Nature and biology3–5 minAn echolocating bat uses the delay and character of returning sound to follow a target. Its calls can change as it approaches prey, connecting the sound it sends with the information it needs next.

Two routes from a young insect to an adult | Speech Topic | speaking.app