The truth behind animal brawls

This exercise is a part of Educator Guide: Fight Like an Animal / View Guide

Directions: These questions are based on the article “Fight like an animal.” Due to the length of the feature article, students can read the introduction and then divide into five groups to concentrate on one section of the article. The sections are: (1) “Deadliest matches,” focused on nematodes (Steinernema longicaudum), (2) “Territorial female slayers,” focused on fig wasps (Pegoscapus sp.), (3) “Walk away,” focused on sea anemones (Actinia equina), (4) “Worth the fight?” focused on Caribbean mantis shrimp (Neogonodactylus bredini) and (5) “Paradoxically peaceful,” focused on Asian rhinoceros beetles (Trypoxylus dichotomus). Each group should answer questions as they relate to the group’s specific animal. Groups should then report their findings to the rest of the class. After the presentation is complete, show the related video embedded in the article, “Fight like an animal.”

1. What animal did your group study?

Possible student response: Nematodes, fig wasps, sea anemones, Caribbean mantis shrimp or Asian rhinoceros beetles.

2. What exactly was your animal competing for?

Possible student response: A mate, a food supply, resource-rich real estate or some combination of those.

3. What weapon did your animal evolve to help it compete?

Possible student response: Nematodes have squeezing muscles and sharp spicules. Female fig wasps have jaws capable of decapitating competitors. Anemones have inflatable toxin-injecting stingers. Caribbean mantis shrimp have clublike arms. Male Asian rhinoceros beetles have long horns.

4. What offensive strategy did your animal employ with that weapon?

Possible student response: Nematodes squeeze rivals to death. Fig wasps decapitate rivals. Anemones inject rivals with a tissue-damaging toxin. Caribbean mantis shrimp pound on the shell of a rival with a club that can accelerate as fast as a bullet shooting out of a .22 caliber pistol. And male Asian rhinoceros beetles use their horns to flick rival males away from female beetles.

5. What counterstrategy do other animals belonging to that species use when confronted by a rival?

Possible student response: Rival nematodes could squeeze or avoid their challengers. Rival fig wasps could attempt to decapitate their challengers. Rival anemones could engage in the battle or “walk away” from a challenger. Rival Caribbean mantis shrimp could outnumber the pounds of a competitor. Rival Asian rhinoceros beetles could stealthily find a way around opponents.

6. What human weapons are similar to the weapon of your animal?

Possible student response: Similar to nematodes: constricting nets or steel traps. Similar to fig wasps: axes or guillotines. Similar to anemones: poison darts. Similar to Caribbean mantis shrimp: fists, clubs, bombs and artillery. Similar to Asian rhinoceros beetles: canes, pry bars, cattle prods and lances.

7. Does your animal tend to kill its rivals or merely send it away?

Possible student response: Nematodes and fig wasps tend to kill. Anemones, Caribbean mantis shrimp and Asian rhinoceros beetles tend to send their opponents away.

8. What factors determine whether an animal will kill its rivals or send it away?

Possible student response: What makes animals fight to death or simply stop fighting in the middle of a battle is still a question for scientists. Some animals, such as anemones, can’t hurt their rival without also harming themselves, so fighting to a rival’s death may also cause serious self-harm. Other animals, such as mantis shrimp, seem to know when they are outmatched in a battle, and will simply stop fighting at a certain point. On the other hand, once a female fig wasp has found her soon-to-be fig, she’ll fight to kill other female arrivals who try to share her fig’s resources. Female fig wasps have evolved lethal weapons (powerful jaws) for this purpose.

9. What questions do you still have after reading the article?

Possible student response: What other interesting animal weapons and competition strategies exist? Is it inherent in human nature to be similarly competitive with other humans over limited resources, or can we work together peacefully and productively? What new weapons could be genetically engineered into animals? How could human-made weapons and competition strategies be designed or improved based on weapons and strategies used by nonhuman animals?

10. After discussing with your classmates the species featured in “Fight like and animal,” which animal would you choose to be in an intraspecies battle? Explain.

Possible student response: I would be a Caribbean mantis shrimp because the battle against my rival wouldn’t be lethal. Also, administering my defenses likely would not weaken my chances of survival. Deploying my weapon wouldn’t physically harm my body structure. I would have an extraordinary weapon to use on my prey.