Teacher’s Questions for Secret Signals

Chemicals called pheromones act as messengers between individuals. Many plants and animals — including squid — respond to such secret chemical signals.

Roger Hanlon, Marine Biological Laboratory, Woods Hole, MA


Before reading:

1. Animals communicate by sound, sight, touch, taste and smell. What might be some of the advantages of communicating by smell?

During reading:

1. When and why did emperor moths ignore Jean-Henri Fabre’s house?

2. Define pheromone.

3. Why would pheromones be useful to moths in search of potential mates at night?

4. List two chemical messages that foraging ants might share with one another.

5. Explain how pheromones can be used to capture insect pests.

6. Describe what Roger Hanlon and his colleagues saw off the shore of Cape Cod, Mass.

7. What was Hanlon’s explanation for the squid behavior he and his team witnessed?

8. What does the Chinese orchid described in the article trick hornets into doing?

9. Could Charles J. Wysocki’s research suggest that pheromones play a role in how we choose a mate? Why or why not?

10. Explain the benefit of using pheromones to trap female sea lampreys in the Great Lakes.

After reading:

1. Dogs use urine to mark their territory. Might pheromones play a role in this activity? Explain why or why not.

2. Review the example given in the story of how pheromones may be at work in adults after watching scary film clips. Do you think people can smell fear? Why would that be helpful?


1. Pheromones can influence the behavior of many animals, even if they are not aware of them. Imagine two behaviors people might want to influence with pheromones. Do you think it would be a good idea to develop artificial pheromones to influence human behavior that way? Why or why not?