Which Animal Is the Deadliest? (2024)

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• Which Animal Is the Deadliest?
• The Extraordinary Powers of the Tiny Mosquito

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In nearly every corner of the planet lurk creatures that will fill your heart with fear. Four-ton hippos in Botswana can chomp a person in half. Tigers in the forests of eastern Russia can shatter bone with one swipe of their massive paws. And the snakes—so many snakes! Cobras and vipers and mambas with venom so potent it can stop a human heartbeat in minutes.

But the most dangerous creature of all doesn’t have crushing jaws or ripping claws or fangs dripping with venom. In fact, you could kill this creature with a flick of your finger.

Creatures that will fill your heart with fear live in nearly every corner of the planet. In Botswana, four-ton hippos can chomp a person in half. Tigers in Russia can shatter bone with one swipe of their massive paws. And the snakes—so many snakes! Cobras, vipers, and mambas with venom so potent it can stop a human heartbeat in minutes.

But what’s the most dangerous creature? It doesn’t have crushing jaws, ripping claws, or fangs dripping with venom. You could kill this creature with a flick of your finger.

It’s the mosquito.

In most parts of the United States, mosquitoes are a nuisance that cause little more than itchy bumps and crusty scabs. In more than 100countries around the world, however, these tiny insects are a disease-spreading menace and a leading cause of death.

Some experts estimate that mosquito-borne illnesses—including dengue fever, West Nile virus, and especially malaria—have killed nearly half of all people who have ever lived. That’s more than have been killed by the rest of Earth’s deadliest creatures combined.

It’s the mosquito.

In most parts of the United States, mosquitoes are only a nuisance. They cause itchy bumps and scabs. But in more than 100 countries, these tiny insects spread disease. And they are a leading cause of death.

Mosquito-borne illnesses include dengue fever, West Nile virus, and malaria. Some experts estimate that these diseases have killed nearly half of all people who have ever lived. That’s more than have been killed by all other deadly creatures combined.

For as long as humans have walked the Earth, mosquitoes have been buzzing in our ears. Mosquitoes bit the bejeweled necks of ancient Egyptian pharaohs and the muscled arms of medieval European warriors. They tormented Chinese empresses and Mayan farmers and George Washington’s troops as they camped at Yorktown.

Malaria too is an age-old menace. The disease has been sickening humans for many thousands of years. It was the Italians who gave malaria its name, centuries ago. Malaria comes from two Italian words: mala, meaning “bad,” and aria, meaning “air.” As the name suggests, early thinkers believed that the disease was caused by moist, foul-smelling air.

This was a logical guess; most people who became sick lived near swamps, marshes, and other wetlands where mosquitoes thrive. It wasn’t until the late 1800s that scientists identified the real culprit. It wasn’t the air spreading the disease. It was the mosquito.

For as long as humans have walked the Earth, mosquitoes have been biting us. Mosquitoes bit ancient Egyptian pharaohs and medieval European warriors. They tormented Chinese empresses, Mayan farmers, and George Washington’s troops.

Malaria too is an age-old menace. The disease has been sickening humans for thousands of years. Italians gave malaria its name, centuries ago. Malaria comes from two Italian words: mala, meaning “bad,” and aria, meaning “air.” As the name suggests, early thinkers believed that moist, bad-smelling air caused the disease.

This was a logical guess. Most people who became sick lived near swamps, marshes, and other wetlands—where mosquitoes thrive. But in the late 1800s, scientists identified the real culprit. It wasn’t air. It was the mosquito.

Over the past century, researchers have learned a great deal more about malaria, including how it spreads. They know that of the 3,500species of mosquitoes, only about 40—all belonging to one group, Anopheles—transmit the disease to humans.

The spread of malaria begins when an infected person is bitten by a female Anopheles mosquito. (Males don’t spread malaria because they don’t feed on blood.) The mosquito uses its needlelike mouth to pierce the person’s flesh. During its “blood meal,” the mosquito gorges itself on the blood of the infected person. Then it flies away.

Days later, when the mosquito is ready for its next meal, it lands on a new person. As the mosquito jabs that person’s flesh, malaria parasites called Plasmodium enter the new victim’s blood.

In this way, bite by itchy bite, about 230 million people are infected with malaria each year. People who live in rural parts of developing countries, where medical care is often difficult to access, are most vulnerable to malaria. Those who become sick suffer high fevers, bone-rattling chills, and painful muscle aches. Most recover—but not all.

In 2021 alone, malaria killed an estimated 619,000 people across Africa, Asia, and Central and South America, according to the World Health Organization. In Africa, where most cases occur, the majority of deaths are among children younger than5.

Over the past century, researchers have learned a lot about malaria, including how it spreads. They know there are 3,500 species of mosquitoes. But only about 40 species—all belonging to one group, Anopheles—transmit the disease to humans.

Here’s how it spreads: A female Anopheles mosquito bites an infected person. (Male mosquitoes don’t feed on blood, so they don’t spread malaria.) The mosquito uses its needlelike mouth to pierce the person’s flesh. During this “blood meal,” the mosquito gorges itself on the blood of the infected person. Then it flies away.

Days later, the mosquito is ready for its next meal. It lands on a new person. As the mosquito jabs that person’s flesh, malaria parasites called Plasmodium enter the new victim’s blood.

About 230 million people are infected with malaria each year. Medical care is often difficult to access in rural parts of developing countries. People there are most vulnerable to malaria. Those who become sick suffer high fevers, bone-rattling chills, and painful muscle aches. Most recover—but not all.

In 2021, malaria killed an estimated 619,000 people across Africa, Asia, and Central and South America, according to the World Health Organization. Most cases occur in Africa. The majority of deaths there are among children younger than 5.

Fortunately, much progress has been made in preventing and treating malaria.

Since 2000, more than 2 billion nets treated with mosquito-killing chemicals have been distributed in malaria-prone regions around the world. The nets are hung over beds to protect people from mosquitoes at night. The nets have significantly reduced the number of malaria cases, but they aren’t a perfect solution. Over time, the chemicals become less effective as mosquitoes adapt.

That’s one reason scientists have been searching for new ways to combat mosquito-borne illnesses. Recently, researchers figured out how to genetically alter male mosquitoes so that their female offspring don’t survive into adulthood. Millions of these genetically altered males are now being grown in labs and released into the wild, where they mate with females. As a result, the number of mosquitoes in Brazil, Panama, and India has decreased.

This approach has its critics, however. Some experts have raised concerns that significantly reducing mosquito populations could harm ecosystems. For example, animals that eat mosquitoes might suffer.

Meanwhile, researchers have been developing promising new medications. In 2021, the first vaccine shown to prevent malaria, Mosquirix, was approved by the World Health Organization. Though the vaccine is groundbreaking, it has been shown to reduce malaria cases only by about 40percent.

And so the search for new weapons in the war on malaria continues. Until scientists discover better ways to prevent and treat this deadly disease, the tiny mosquito will remain the most fearsome creature on the planet.

Fortunately, progress has been made in preventing and treating malaria.

Since 2000, more than 2 billion nets treated with mosquito-killing chemicals have been distributed in malaria-prone regions around the world. The nets are hung over beds. This protects people from mosquitoes at night. The nets have greatly reduced the number of malaria cases. But they aren’t a perfect solution. Over time, the chemicals become less effective as mosquitoes adapt.

So scientists keep searching for new ways to combat mosquito-borne illnesses. Recently, researchers figured out how to genetically alter male mosquitoes so that their female offspring don’t survive into adulthood. Millions of these males are now being grown in labs and released into the wild. Then they mate with females. As a result, the number of mosquitoes in Brazil, Panama, and India has decreased.

But some experts are concerned about this solution. They worry that it could harm ecosystems. For example, animals that eat mosquitoes might suffer.

Meanwhile, researchers have been developing new medications. In 2021, the World Health Organization approved Mosquirix. It’s the first vaccine shown to prevent malaria. The vaccine is groundbreaking. But it reduces malaria cases only by about 40 percent.

And so scientists keep trying to discover better ways to prevent and treat this deadly disease. Until that happens, the tiny mosquito will remain the most fearsome creature on the planet.

The Extraordinary Powers of the Tiny Mosquito

Do Now: Solve a Riddle (5 minutes)

• Display the following riddle for your students to solve as they enter the room:

My entire life cycle lasts 8-10 days.

I usually travel only 100-200 feet at a time.

My max speed is 1.5 miles per hour.

I am the deadliest creature on Earth. Some experts estimate that I’ve killed half of all people who’ve ever lived.

I am important in the food chain: I provide food for bats, fish, birds, and frogs.

I am a pollinator. That is, I move pollen, which helps plants produce fruits and seeds.

Researchers think my spit could help cure human diseases.

What am I?

• The answer is the mosquito. Direct students’ attention to page 11 or the top of the digital story page and discuss: Why do you think the article’s opening image features a tiger, a cobra, a shark, and other threatening animals? Are you surprised that the deadliest animal is the mosquito? How might this tiny insect be deadly?

Preview Vocabulary (10 minutes)

• Project the Google Slides version of Vocabulary Definitions and Practice on your whiteboard. Review the definitions and complete the activity as a class. Highlighted words: adapt, nuisance, potent, prone, rural. Audio pronunciations of the words and a read-aloud of the definitions are embedded on the slides. Optionally, print the PDF version or share the slideshow link directly to your LMS and have students preview the words and complete the activity independently before class.

Do Now: Solve a Riddle (5 minutes)

• Display the following riddle for your students to solve as they enter the room:

My entire life cycle lasts 8-10 days.

I usually travel only 100-200 feet at a time.

My max speed is 1.5 miles per hour.

I am the deadliest creature on Earth. Some experts estimate that I’ve killed half of all people who’ve ever lived.

I am important in the food chain: I provide food for bats, fish, birds, and frogs.

I am a pollinator. That is, I move pollen, which helps plants produce fruits and seeds.

Researchers think my spit could help cure human diseases.

What am I?

• The answer is the mosquito. Direct students’ attention to page 11 or the top of the digital story page and discuss: Why do you think the article’s opening image features a tiger, a cobra, a shark, and other threatening animals? Are you surprised that the deadliest animal is the mosquito? How might this tiny insect be deadly?

Preview Vocabulary (10 minutes)

• Project the Google Slides version ofVocabulary Definitions and Practiceon your whiteboard. Review the definitions and complete the activity as a class. Highlighted words:adapt, nuisance, potent, prone, rural. Audio pronunciations of the words and a read-aloud of the definitions are embedded on the slides. Optionally, print the PDF version or share the slideshow link directly to your LMS and have students preview the words and complete the activity independently before class.

“Which Animal Is the Deadliest?”

• Invite a volunteer to read the As You Read box on page 12 or at the top of the digital story page.

• Read the article once as a class. (Differentiation: Share the lower-Lexile version of the article.) Optionally, have students listen to the article read-aloud while they follow along. The read-aloud is located in the Resources tab in Teacher View and at the top of the story page in Student View.

• Divide students into groups to read the article again and respond to the following Close-Reading and Critical-Thinking Questions, also located in the Resources tab.

Close-Reading Questions(20 minutes)

1. How does author Lauren Tarshis develop the idea that mosquitoes have been a problem for humans for thousands of years? (key ideas and details) In the introduction, Tarshis provides a statistic about mosquito-borne illnesses that illustrates how long they have plagued humans: Some experts estimate they’ve killed nearly half of all people who have ever lived. In the section “An Ancient Problem,” she provides examples of humans from various times and places who dealt with the problem of mosquitoes: Egyptian pharaohs, Chinese empresses, Mayan farmers, and George Washington’s troops. In the text feature “Malaria Through Time,” she provides details about the traces of malaria found in King Tut’s 3,500-year-old mummy and the roots of an effective medicine used to treat malaria today—the wormwood plant used by Chinese healers to treat the disease 1,600 years ago.

2. Why are mosquitoes a problem for humans? (problem and solution) Mosquitoes are a problem for humans because they transmit deadly illnesses such as dengue fever, West Nile virus, and malaria. About 230 million people are infected with malaria each year. In 2021, malaria killed more than 600,000 people across Africa, Asia, and Central and South America. People in rural parts of developing countries with little access to medical care are especially at risk.

3. In your own words, how is malaria transmitted? (cause and effect) When a female mosquito bites a person infected with malaria, the mosquito slurps up blood that contains malaria parasites. A few days later, when the mosquito has its next blood meal, these parasites get injected into the new person being bitten.

4. What solutions to malaria have been explored? Have any worked? (problem and solution) Some solutions that have been explored are nets coated with mosquito-killing chemicals to protect people while they sleep, the genetic alteration of male mosquitoes so that female offspring don’t survive, a medicine called artemisinin, a vaccine called Mosquirix, the spraying of an insecticide called DDT, and the killing of mosquito larvae with essential oils and yeast. Many of these solutions have led to a reduction in malaria cases, but they have not been effective enough or have been otherwise problematic. For example, over time mosquitoes adapt to the chemicals on the nets, and the vaccine reduces malaria cases by only 40 percent. DDT successfully killed mosquitoes in the U.S., but it turned out to be extremely harmful to humans and the environment, and it is now banned in many nations. As Tarshis writes, “the search for new weapons in the war on malaria continues.”

“The Extraordinary Powers of the Tiny Mosquito"

• Give students a few minutes to study the infographic.

• As a class, discuss the following Close-Reading and Critical-Thinking Questions, which apply to the article and the infographic.

Close-Reading Questions (5 minutes)

1. Consider the words each author uses to describe or refer to mosquitoes. Compare the words they use and how the words create each author’s tone. (word choice, tone) Tarshis uses the adjectives “deadliest,” “dangerous,” and “fearsome” to describe mosquitoes. She refers to them as “a nuisance” and “a disease-spreading menace.” She uses verbs like “combat,” “tormented,”and “battling” when describing humans’ relationship with mosquitoes. She is full of concern for human health and is mostly anti-mosquito. Adee Braun, on the other hand, calls mosquitoes “Magic Spitters,” “Super Sniffers,” and “Plant Growers.” She describes their senses and abilities as “extraordinary.” Braun sounds as though she admires and is impressed by mosquitoes.

2. Compare the details Tarshis and Braun include related to the topic of disease. How do these details affect your understanding of mosquitoes? (author’s purpose) Tarshis’s article describes the problem of serious mosquito-borne illnesses. Braun’s infographic presents a flip side: She explains that mosquitoes’ saliva contains chemicals that stop blood from clotting and may help treat human diseases caused by blood clots. Taken together, these details show that while mosquitoes spread dangerous illnesses to people, they may also have the ability to help heal people.

   *For a deeper dive into tone, show the Scope Toolkit “What’s the Tone?” video. Pass out our Tone Words reference page, a bank of words to help students identify tone in any text.

Critical-Thinking Question (5 minutes)

1. How would you characterize mosquitoes: fearsome, extraordinary, or both? In what ways, if any, do you think differently about mosquitoes after reading these articles? Answers will vary.

“Which Animal Is the Deadliest?”

• Invite a volunteer to read the As You Read box on page 12 or at the top of the digital story page.

• Read the article once as a class.(Differentiation: Share the lower-Lexile version of the article.)Optionally, have students listen to thearticle read-aloudwhile they follow along. The read-aloud is located in the Resources tab in Teacher View and at the top of the story page in Student View.

• Divide students into groups to read the article again and respond to the followingClose-Reading and Critical-Thinking Questions, also located in the Resources tab.

Close-Reading Questions(20 minutes)

1. How does author Lauren Tarshis develop the idea that mosquitoes have been a problem for humans for thousands of years?(key ideas and details)In the introduction, Tarshis provides a statistic about mosquito-borne illnesses that illustrates how long they have plagued humans: Some experts estimate they’ve killed nearly half of all people who have ever lived. In the section “An Ancient Problem,” she provides examples of humans from various times and places who dealt with the problem of mosquitoes: Egyptian pharaohs, Chinese empresses, Mayan farmers, and George Washington’s troops. In the text feature “Malaria Through Time,” she provides details about the traces of malaria found in King Tut’s 3,500-year-old mummy and the roots of an effective medicine used to treat malaria today—the wormwood plant used by Chinese healers to treat the disease 1,600 years ago.

2. Why are mosquitoes a problem for humans?(problem and solution)Mosquitoes are a problem for humans because they transmit deadly illnesses such as dengue fever, West Nile virus, and malaria. About 230 million people are infected with malaria each year. In 2021, malaria killed more than 600,000 people across Africa, Asia, and Central and South America. People in rural parts of developing countries with little access to medical care are especially at risk.

3. In your own words, how is malaria transmitted?(cause and effect)When a female mosquito bites a person infected with malaria, the mosquito slurps up blood that contains malaria parasites. A few days later, when the mosquito has its next blood meal, these parasites get injected into the new person being bitten.

4. What solutions to malaria have been explored? Have any worked?(problem and solution)Some solutions that have been explored are nets coated with mosquito-killing chemicals to protect people while they sleep, the genetic alteration of male mosquitoes so that female offspring don’t survive, a medicine called artemisinin, a vaccine called Mosquirix, the spraying of an insecticide called DDT, and the killing of mosquito larvae with essential oils and yeast. Many of these solutions have led to a reduction in malaria cases, but they have not been effective enough or have been otherwise problematic. For example, over time mosquitoes adapt to the chemicals on the nets, and the vaccine reduces malaria cases by only 40 percent. DDT successfully killed mosquitoes in the U.S., but it turned out to be extremely harmful to humans and the environment, and it is now banned in many nations. As Tarshis writes, “the search for new weapons in the war on malaria continues.”

“The Extraordinary Powers of the Tiny Mosquito"

• Give students a few minutes to study the infographic.

• As a class, discuss the following Close-Reading and Critical-Thinking Questions, which apply to the article and the infographic.

Close-Reading Questions (5 minutes)

1. Consider the words each author uses to describe or refer to mosquitoes. Compare the words they use and how the words create each author’s tone.(word choice, tone)Tarshis uses the adjectives “deadliest,” “dangerous,” and “fearsome” to describe mosquitoes. She refers to them as “a nuisance” and “a disease-spreading menace.” She uses verbs like “combat,” “tormented,”and “battling” when describing humans’ relationship with mosquitoes. She is full of concern for human health and is mostly anti-mosquito. Adee Braun, on the other hand, calls mosquitoes “Magic Spitters,” “Super Sniffers,” and “Plant Growers.” She describes their senses and abilities as “extraordinary.” Braun sounds as though she admires and is impressed by mosquitoes.

2. Compare the details Tarshis and Braun include related to the topic of disease. How do these details affect your understanding of mosquitoes?(author’s purpose)Tarshis’s article describes the problem of serious mosquito-borne illnesses. Braun’s infographic presents a flip side: She explains that mosquitoes’ saliva contains chemicals that stop blood from clotting and may help treat human diseases caused by blood clots. Taken together, these details show that while mosquitoes spread dangerous illnesses to people, they may also have the ability to help heal people.

   *For a deeper dive into tone, show theScope Toolkit “What’s the Tone?” video. Pass out ourTone Words reference page, a bank of words to help students identify tone in any text.

Critical-Thinking Question (5 minutes)

1. How would you characterize mosquitoes: fearsome, extraordinary, or both? In what ways, if any, do you think differently about mosquitoes after reading these articles?Answers will vary.

• Have students complete the Featured Skill Activity: Synthesis. This activity prepares them to respond to the writing prompt on page 15 in the printed magazine and at the bottom of the digital story page:

You just read two texts about mosquitoes. What is each author’s purpose? How does reading both texts give you a more complete understanding of mosquitoes than reading just one of the articles would? Answer both questions in a short essay. Use text evidence.

• Alternatively, have students choose a task from the Choice Board, a menu of culminating tasks. (Our Choice Board options include the writing prompt from the magazine, differentiated versions of the writing prompt, and additional creative ways for students to demonstrate their understanding of a story or article.)

• Have students complete theFeatured Skill Activity: Synthesis. This activity prepares them to respond to the writing prompt on page 15 in the printed magazine and at the bottom of the digital story page:

You just read two texts about mosquitoes. What is each author’s purpose? How does reading both texts give you a more complete understanding of mosquitoes than reading just one of the articles would? Answer both questions in a short essay. Use text evidence.

• Alternatively, have students choose a task from theChoice Board, a menu of culminating tasks. (Our Choice Board options include the writing prompt from the magazine, differentiated versions of the writing prompt, and additional creative ways for students to demonstrate their understanding of a story or article.)