Symmetry in Nature

Reflective symmetry happens when you can draw a line through an object and both sides mirror each other. This line is called the line of symmetry.

Most animals show this kind of symmetry. It helps with balance, coordination, and sensory processing. Two eyes, two ears, two arms, two legs — all arranged in a way that keeps us steady and lets us interact smoothly with the world.

Butterflies are practically nature’s symmetry influencers. Their wings mirror each other in color, shape, and pattern — a feature that can camouflage them, scare off predators, and even attract mates. 

Humans are also bilaterally symmetrical. Studies show people often find symmetrical faces more attractive (Chong & Zelcer, 2024). Why? Because facial symmetry is considered a subtle sign of healthy development and strong genes.

Now picture a starfish spinning. Even as it turns, its shape stays consistent. That’s rotational symmetry, also known as radial symmetry. It means you can rotate an object around a central axis, and it’ll look the same at regular intervals.

The number of times it matches up during a full 360° turn is called its order of symmetry. Divide 360° by the angle of repetition to find the order.

This kind of symmetry is especially useful for stationary or slow-moving organisms — if you're stuck in place, it pays to be equally functional in all directions.

Starfish have five arms spaced evenly around a center — they have rotational symmetry of order 5. This lets them sense and respond to their surroundings in any direction. If they lose an arm, their symmetry helps guide regrowth — sometimes, even a single arm can regenerate into a whole new starfish!

Snowflakes show six-fold rotational symmetry thanks to hydrogen bonding. Water molecules arrange themselves into a hexagonal lattice, optimizing attraction and reducing repulsion, which makes the freezing process more efficient. It also helps snowflakes maintain balance as they fall, ensuring they are aerodynamically stable in the air.

Many flowers also exhibit rotational symmetry, particularly those with five-fold, six-fold, or even eight-fold symmetry. This symmetry helps attract pollinators, as bees and insects can approach from any direction and still encounter the same set of petals, making the flower more accessible.

This type shows up when a pattern repeats by sliding in a direction — like copy-pasting a shape again and again without rotating or flipping it.

Zebra stripes, snake scales, and honeycomb cells use translational symmetry for practical reasons.

Zebras show translational symmetry in their stripes, which repeat consistently across the body. These patterns disrupt predator vision, help regulate body temperature, and may even serve as zebra “name tags” for individual recognition — barcode biology!

Honeycombs are made up of repeating hexagonal cells. This shape uses the least wax while storing the most honey — a natural engineering win (Smith et al., 2021)! Some scientists think bees start with circular cells and physics shapes them into hexagons; others think bees instinctively build this way. Either way, it’s brilliant.