🦊 Predator and Prey: The Population Game

Grade 2 Life Science, Unit 2 — Lesson 4

📚 Grade: 2nd Grade ⏱️ Duration: 45 minutes 🔬 Subject: Life Science — Ecosystems 🌱 Unit: 2-LS2 Ecosystems
🦊🐇🌿⚖️🌍
Predators and prey keep each other's populations in balance.
📋 NGSS Standard:
2-LS2-1 — Make observations of plants and animals to compare the diversity of life in different habitats.

🎯 Learning Goals

📦 Materials

🏠 What You Need

✅ No specialty purchases needed — just paper scraps and open space!

📖 Vocabulary

Predator An animal that hunts and eats other animals
Prey An animal that is hunted and eaten by another animal
Population The total number of one kind of animal living in an area
Balance When predator and prey populations stay at healthy levels over time
Reproduce To have babies and make more of your species
Survive To stay alive despite challenges from predators or the environment

🌍 Background

In every ecosystem, some animals eat other animals. The animal that hunts is called the predator. The animal being hunted is called the prey. Foxes hunt rabbits. Hawks hunt mice. Owls hunt voles. These relationships keep ecosystems healthy by preventing any one species from becoming too numerous.

Predator and prey populations are connected like a seesaw. When there are lots of rabbits (prey), foxes (predators) have plenty to eat and their population grows. But more foxes eat more rabbits, so rabbit numbers start to drop. With fewer rabbits, some foxes go hungry and fox numbers drop too. With fewer foxes, rabbits bounce back — and the cycle starts again.

This up-and-down cycle keeps ecosystems in balance. It is not cruel — it is the way ecosystems stay healthy. When humans remove predators from an ecosystem (such as by hunting wolves away from a forest), prey populations can explode, eat all the vegetation, and cause the ecosystem to collapse. Every predator plays a role, even the scary ones.

🔬 Activity: Population Tag

💡 Setup: 1 player = fox (predator). All other players = rabbits (prey). Each rabbit starts with 2 red cards ("lives") held in their hands. This works great with just 2 people (one adult as fox, one child as rabbit) or a whole family!
Round Setup: Fox stands at one end of the room. Rabbits scatter in the space. Give each rabbit 2 red cards to hold.
Play (1 minute each round): Fox chases rabbits and tags them. Each tag = fox takes 1 life card. A rabbit with 0 cards is "eaten" and sits down for that round.
Count after each round: How many rabbits survived? How many were eaten? Write the numbers in your tally sheet.
Reproduce: Each surviving rabbit gets 1 new card (they had a baby rabbit!). Fox stays in the game if they tagged at least 1 rabbit.
Repeat for 5 rounds total. After Round 5, look at your numbers. Did the rabbit population go up and down in a pattern?

💬 Discussion Questions

🗣️ Question 1: What happened to the rabbit population over 5 rounds? Did it stay the same, or did it change?

Suggested answer: Usually the population zigzags! When rabbits are plentiful, the fox catches many and rabbit numbers drop. When rabbit numbers drop, the fox struggles to catch enough — then rabbits recover. This is the natural predator-prey cycle. Even in a short 5-round game, students often see this balance develop.

🗣️ Question 2: What would happen if we added 3 more foxes to the game?

Suggested answer: More foxes would eat more rabbits faster, driving the rabbit population down quickly. With very few rabbits left, the many foxes would struggle to find food and some would "starve." Eventually the system might balance at a lower level — or collapse if the rabbits go extinct. This is why introducing or removing predators from an ecosystem has huge ripple effects.

🗣️ Question 3: If all the rabbits disappeared from an ecosystem, what would happen to the foxes?

Suggested answer: The foxes would lose their food source. Some might find other prey (mice, birds), but if rabbits were their main food, the fox population would shrink significantly. This shows that predators NEED their prey to survive — they are just as dependent on each other as plants and pollinators.

🦊 Student Worksheet — Predator and Prey

Name: ________________________________      Date: ________________

Part 1 — Population Tally Table

Record your data after each round of Population Tag.

Round 🐇 Rabbits at Start 🦊 Rabbits Eaten 🐇 Rabbits Survive 🐇 After Reproduce
1
2
3
4
5

Part 2 — Graph the Rabbit Population

Plot your rabbit "After Reproduce" number for each round. Connect the dots with a line. What shape does it make?

108642
R1R2R3R4R5

Round Number →

Part 3 — Vocabulary Match

Draw a line from each word to its definition.

Predator

Prey

Population

Balance

An animal that is hunted

When populations stay at healthy levels

The total number of one kind of animal in an area

An animal that hunts other animals

Part 4 — Reflection

I noticed that when the fox population goes up, the rabbit population goes .

This happens because .

👩‍🏫 Parent/Teacher Notes