Biosecurity Dominos

See how quickly illnesses can spread – or be stopped in their tracks.

About the Activity

Viruses and other illnesses can spread rapidly from one person to another. Think about when someone in your family gets a cold: A lot of times it quickly spreads to others. That happens on the farm, too, because when one animal gets sick it can easily spread that illness to others – after all, there’s only so much space in a barn!

This is the second in a four-part educational series about preventing and treating illness in animals. View all activities at 4-H Veterinary Science: Stopping Sickness.


Grades: 6-8
Topic: Animal Science
Estimated Time: 25 minutes


Supported by the Agriculture and Food Research Initiative, Education and Workforce Development Program.

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These simple materials will get you started.

  • Dominos, Jenga blocks, or something similar.
  • A checkerboard, table top or some other small, flat surface.
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Activity Steps
Follow these steps to complete the activity.

In this activity, kids use dominos (or something similar), arranging them in different ways to simulate how illnesses are spread and stopped. Each block represents an animal, and each fallen block represents an animal getting sick.


  1. Place 15-20 dominos on your flat surface in a space about the size of a checkerboard. Arrange them and space them so that when you knock one down, it will hit the next one, which will hit the next one, and so on, until all the dominos are knocked down.Did You Know? Diseases and other illnesses spread in a lot of ways. One of these ways is when an animal directly puts the pathogen (any microorganism that can cause an illness), into another animal’s body. If that sounds strange, think about one of the most common ways that happens – mosquitoes. Animals like mosquitoes that directly infect another animal are called vectors.
  1. Now, set the dominos up again. This time, arrange them so that one domino knocks down all the others, except for one.Did You Know? An animal that is carrying an illness but doesn’t show any signs, or symptoms, is called a reservoir.
  2. Finally, set the dominos back up and arrange them so that when you knock one down, none of the others are knocked down.Did You Know? Biosecurity is an action taken to prevent sickness from spreading. Some forms of biosecurity are by increasing the physical distance between animals (or people) apart, quarantining sick animals (keeping the sick ones apart from the well ones), and by using vaccines to make animals immune to certain illnesses (being immune means your body has the ability to resist a given illness).

Reflection Questions
Questions to deepen wonder and understanding.

  1. How are the blocks that you used for the activity a model for how sickness can spread between animals or people?
  2. What type of diseases have you seen or heard about spreading between animals, or between people?
  3. Have you heard of any illnesses that can spread between both animals and people?
  4. What do you do to prevent germs or illnesses from spreading in your home or at your school?
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Investigate and Explore
Take what you've learned to the next level to learn more and explore the possibilities.

You’re probably a lot more familiar with the concept of disease spread now than you were before the coronavirus pandemic broke out in 2020. But the same principals have always applied to limiting the spread of sickness, and farmers have always been especially concerned with that. That’s because if one animal gets sick, it is very easy for the rest of the animals around it to get sick, and those animals are a farmer’s livelihood.


Now, we all understand how important it is to limit the spread of germs and pathogens. And the same fundamentals that mattered before the coronavirus still matter now: regularly washing your hands, sneezing into your elbow, and limiting your exposure to other sick people always have been and always will be the best ways to keep yourself – and others – healthy.

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Shop 4-H Curriculum and Products

Shop 4-H offers university-backed STEM curriculum, educational kits, products and supplies to help you continue exploring animal science and more!

Click on the tiles below to learn more and add items to your cart.

From Airedales to Zebras Veterinary Science curriculum from Shop 4-H

From Airedales to Zebras

Grades: 3-5


Introduces youth to the normal animal, basic anatomy and systems, elementary principles of disease and careers with animals.



Veterinary Science curriculum set of 4 from Shop 4-H

Veterinary Science Set of 4

Grades: 3-12


The full set of Veterinary Science curriculum includes beginner through advanced levels and the accompanying helper's guide.



Animal Behavior curriculum digital download from Shop 4-H

Animal Behavior Digital Download

Grades: 9-12


Designed to be facilitated in small groups, activities cover animal care concepts and issues in biomedical research and food safety.



Horse Science curriculum set of 2 from Shop 4-H

Horse Program Set of 2

Two of our most popular and time-tested guides that include scientific and practical horse information. Set includes one copy each of Horse Science and Horses and Horsemanship.


All About Dogs curriculum from Shop 4-H

All About Dogs

Grades 3-8


Learn how dogs think and the meaning behind their body language, how to keep dogs happy and healthy and  the roles they play in our lives.



Dog curriculum set of 4 from Shop 4-H

Dairy Goat Set of 4

Grades: 3-12


The full set of Dairy Goat curriculum includes beginner through advanced levels and the accompanying helper's guide.




View the full collection of Animal and Agricultural Science curriculum on Shop 4-H.

Brought to you by:

This work is supported by the Agriculture and Food Research Initiative, Education and Workforce Development Program, grant no. 2021-67037-33376/ Project Accession No. 1024940, from the U.S. Department of Agriculture, National Institute of Food and Agriculture.

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