Magnetic Bacteria May Help Animals Navigate Earth

A researcher created a database with hundreds of millions of animal DNA sequences contain types of magnetic bacteria that may help animals sense Earth's magnetic field

Hiya!

Sight, smell, taste, touch, and hearing are the five primary senses we humans use to learn about and navigate our surroundings, but we aren’t the only animals to possess them. In fact, most other animals on Earth can see, smell, taste, touch, and hear. And some of them have additional senses we don’t possess and are just beginning to understand — like magnetoreception.

Animals with magnetoreceptive abilities can sense Earth’s magnetic field. Some use it to hunt, while others use it to navigate during migration. However, scientists have yet to understand how precisely they sense it. Plenty of theories have been proposed, of course, but one idea involving magnetic bacteria is gaining traction lately.

Earth’s Magnetic Field

As you likely know, Earth is surrounded by a magnetic field called the magnetosphere. This field makes compass needles point North and, more importantly, protects Earth from dangerous space conditions, like solar flares, that could decimate the planet.

The churning and swirling of molten metal near the Earth’s core as it rotates around the Sun generates electrical currents that flow thousands of miles per hour and reach hundreds of miles wide. These electrical currents travel in a closed, continuous loop, flowing into Earth through its top and exiting through its bottom, thus creating Earth's northern and southern poles with opposite polarities, like a bar magnet.

This magnetic force field isn’t a spherical bubble, but shaped more like a sideways ice cream cone. Solar winds on Earth’s Sun-facing side compress the field, making it round. Meanwhile, on the night-facing side, the field stretches far into the distance like a tail.

The strength and direction of Earth’s magnetic field across the planet’s surface make it useful for navigation, especially since it’s a constant force when other spatial cues, like light, are not.

However, constant as Earth’s magnetic field may be, it isn’t fixed. It moves, and thus so do the planet’s poles.

In fact, the planet’s magnetic poles have flipped several times over billions of years and have shifted over 600 miles just since 1831. Even as recently as January 2025, scientists discovered our magnetic north pole is moving toward Europe, specifically Siberia, and behaving in ways never seen before.

Magnetoreception

Even with a moving map, aka magnetic field, many animals —including birds, butterflies, whales, sharks, wildebeests, sea turtles, and more — use it to navigate the planet so accurately that they can travel thousands of miles and return to shockingly precise locations, like a specific beach.

Meanwhile, other animals, such as foxes and at least some dogs, appear to use Earth’s magnetic field for different things, like hunting.

Some research suggests that humans can sense Earth’s magnetic field to some degree, too, but likely only subconsciously. And in typical human fashion, we’re curious, even envious, when animals possess abilities we do not. So it’s no wonder scientists want to understand magnetoreception, especially since it seems almost common among the animal kingdom.

Sensory biologist at Lund University in Sweden (one of the top 100 universities in the world), Eric Warrant explains in his research from 2021,

“It’s (magnetoreception is) the last sense we effectively know nothing about. The solution of this problem I would say is the greatest holy grail in sensory biology.”

Over the decades, scientists have identified a few ways animals might sense Earth’s magnetic field. For instance, research suggests that at least some birds can literally see it, like a map, and nerves within shark skin can detect electric and magnetic fields.

Yet, researchers have not found any specific, unifying mechanism or organ dedicated to detecting Earth’s magnetic field.

How Do They Do It?

Even though magnetoreception remains mysterious, scientists aren’t short on theories about how it might work. One of the more prevalent ideas involves quantum mechanics and is somewhat mind-boggling, so bear with me.