Do Bulls Really React Aggressively to the Color Red?

For years, the image of a bull charging at a red cape has been a symbol of rage and aggression. However, is it really the red color that sets the bull off? Surprisingly, this widely believed idea is just a myth! Science has shown that bulls do not react to red at all. Instead, it’s something completely different that makes them charge.

In this article, we’ll break down the myth, explain the science, and uncover the real truth.

Where Did This Myth Come From?

The belief that bulls hate the color red comes from bullfighting, a tradition in Spanish culture. During the fight, the matador uses a red cape, called a muleta, to attract and direct the bull. The bull’s aggressive charge toward the cape led people to assume that the red color was the cause.

However, this idea became even more popular through movies, cartoons, and idioms. For example, the phrase “seeing red” became synonymous with anger, further reinforcing the myth.

The Science: Bulls Can’t See Red

Here’s the truth: bulls are colorblind to red. Like many other animals, bulls have dichromatic vision. This means they can only see two main colors:

• Blue
• Yellow

On the other hand, they cannot distinguish red from gray or black. In other words, to a bull, the bright red cape looks no different from a dull gray cloth.

What Actually Makes Bulls Charge?

If bulls can’t see red, then why do they charge at the cape? The answer is simple: movement, not color. Here’s what really happens:

1. The Motion of the Cape: Bulls are naturally reactive to sudden, repetitive movements. When the matador waves the cape, the bull perceives it as a threat and instinctively charges.
2. The Stressful Environment: The loud crowd, bright lights, and unfamiliar setting of a bullfight put the bull on high alert. Therefore, it’s already predisposed to react aggressively.
3. Fight or Flight Instinct: Like many animals, bulls respond to perceived threats with their natural instincts. The waving cape triggers their instinct to defend or attack.

In short, it’s not about the color—it’s about the movement.

Why Is the Cape Red Then?

Now that we know bulls don’t react to red, you might be wondering: why do matadors use a red cape? There are two main reasons:

1. Symbolism: The color red symbolizes danger, blood, and energy, which adds drama to the performance.
2. Practicality: The red color helps hide any bloodstains, making the fight look less graphic for the audience.

Therefore, the red cape is primarily for showmanship and tradition—not for the bull’s reaction.

The Experiment That Debunked the Myth

In a famous experiment, researchers tested bulls with capes of different colors—red, white, and blue. Here’s what happened:

• When the capes were still, the bulls ignored them completely.
• When the capes were waved, the bulls charged at all of them equally, regardless of color.

This experiment proved that the movement of the cape, not its color, is what makes bulls charge.

The Takeaway: Bulls Don’t “See Red”

To summarize:

• Bulls are colorblind to red.
• They react to motion, not the color of the cape.
• The red cape is used for dramatic effect and tradition—not because bulls hate red.

So, the next time someone says bulls get angry at the color red, you can confidently say, “That’s a myth!”