Flying Spiders Explained: The Physics of Ballooning

By Pankaj Kumar|Last Updated: July 12, 2026|

Key Takeaways

Spiders fly using a technique called ballooning, not wings.
Earth’s atmospheric electric field (~100 V/m at the surface) provides the lift force.
A spider needs a negative charge of roughly 9.81 microcoulombs to become airborne.
Spiderlings can survive approximately 25 days traveling through the air.
Spiders balloon to spread offspring, access food, and improve survival odds.

If someone tells you that spiders also fly, you will probably think that the person has gone mad. How can spiders fly without any wings? Are flying spiders for real? If yes, why do they even fly? What is the need to fly? We will answer these questions in this article. Understanding the physics behind this phenomenon is a great way to see how physics tutoring connects classroom concepts to the natural world.

Can Spiders Fly?

Are flying spiders real? Yes they are! Spiders do fly but not with their wings. They use a ballooning technique to fly and it is very efficient in moving them from one place to another.

Sailors have reported seeing spiders coming to their ships as much as 990 miles away from the coast. Biologists have confirmed that the Spiderlings can survive for approximately 25 days while traveling in the air. (See Source 4)

What Is the Ballooning of Spiders?

See the image below to get an idea what ballooning is all about.

Stages of ballooning take-off observed in large spiders

Image from an observational study of ballooning in large spiders depicting stages of ballooning take off (Click here for Image courtesy)

Physics Behind Flying Spiders

Starting with F = qE

A spider needs to balance gravitational force on it by electric force acting on it, and then only it can fly. Your Physics equation sheet will show you the formula F=qE, which means electric force F is equal to charge on the object times the electric field it is immersed in. Students working through AP Physics will recognize this as a direct application of Coulomb’s framework for electric forces.

Source of Electric Field E

Here we need to know the electric field in the earth’s atmosphere because the spider will be immersed in it while flying. Before we move further, we must identify how the earth gets its electric field. Free charges come from cosmic galactic rays or CGR.

Thunderstorms play a significant role in charging the earth, creating a potential difference. It is close to 250,000 Volts spread over 50 km from the earth’s surface to maximum cloud height, which is vast. The free charges brought to earth by cosmic galactic rays can flow as a global atmospheric electric circuit or GEC.

Earth’s surface has a negative excess negative charge. Earth’s atmosphere has a positive charge. So the electric field on earth is pointing in the downward direction. (See Source 2)

How to Calculate Electric Field E

Electric fields can be calculated from the above data and using the equation from equation sheet deltaV=-E*dr.

On an average the electric field E= V/r=250000 volt/50000m=5 v/m in downward direction.

But this is just an average. Close to the earth’s surface, where most of the charge lies, the electric field is relatively more powerful than this average value. At the earth’s surface, its value is close to a hundred V/m. (See Source 3)

This kind of multi-step field calculation is exactly the type of problem explored in guides on how to approach complex topics in physics.

Charge on the Spider q

This value is very much needed to find the charge on the spider. Since the electric force on the spider gets balanced by its weight, we must know the electric field to calculate the electric charge. The weight of a spider can be found easily by measuring or searching on Google.

Force Balancing: qE = mg

Now comes the force balancing part. As we have seen, electric force equals F=qE, where q is the charge on a spider and E is the earth’s electric field.

The spider’s weight is m*g where m= mass of spider and g=9.81 m/s^2.

To balance these two, we must have qE=mg. So, q=mg/E.

The sign of the charge on the spider must be negative; then, only the spider can have an upward electric force. A positive charge on the spider will create a downward electric force in the same direction as the earth’s gravitational pull downwards, which won’t make the spider weightless. So spider charge must be negative only.

This force-balancing logic connects naturally to the broader study of motion in two dimensions in physics, where resolving forces along different axes is a core skill.

Calculations

Assumption: mass of spider is 0.1 grams.

q=mg/E= 0.1*9.81/(1000*100)= 9.81 micro coulomb.

Is It Reasonable?

Yes, it is very reasonable. When we comb our hair and then try to lift pieces of paper, we can do that easily. So a spider that has a mass of the order of paper pieces can also get enough charges to become airborne.

If you find these electrostatics concepts challenging, exploring the top benefits of learning physics online may help you find the right approach. For those studying electricity and magnetism at an advanced level, working with an AP Physics 2 tutor can make these field concepts much clearer.

Why Do Spiders Fly?

Although we do not know yet why the spiders fly, we can trace their origin to life in general.

The most important aim for any living being is to reproduce, or else their species will disappear from the earth. To do so, they try to minimize the risk as much as possible. They try to spread their offspring to various parts of the earth.

It gives them more chance to survive in a catastrophe. Also, it gives them access to more food and place to stay.

You might have heard about the Siberian birds. They cross the mighty Himalayas in flocks when Siberia gets too cold. They come to the Indian peninsula, which is quite pleasant, and have plenty of food for them.

The Himalayas are the highest mountains globally, and crossing them is an adventure. However, they do it to survive and reproduce. It is survival instinct at its best.

Spiders fly so that they do not get stuck in the same place, and they can spread their offspring to various parts of the world, giving them a better chance to survive.

Students who enjoy connecting physics to real-world phenomena like this will find the benefits of an AP Physics tutor online worth reading. For those tackling mechanics and electromagnetism together, a tutor for AP Physics C can bridge both domains effectively.

Food for thought — Can snakes fly?

Sources

https://www.youtube.com/watch?v=vyp8YAyawmI (to understand how spiders fly. Made by national geographic.)
https://drtheory.com/spiders-fly-using-earths-electric-field/
https://sites.science.oregonstate.edu/~mcintyre/COURSES/ph431_F12/examples/EarthCharge.pdf
https://en.wikipedia.org/wiki/Ballooning_(spider)