Munchrd?
Munchrd: Why do the northern lights happen?Nature

Why do the northern lights happen?

The northern lights (aurora borealis) happen when charged particles from the Sun, mostly electrons, are guided by Earth's…

✓ fact-checked
Munchrd: Can octopuses really use mirrors?Nature

Can octopuses really use mirrors?

Yes, in a specific and remarkable way. A 2026 Dartmouth study showed octopuses learning to use a mirror as a tool to locate…

✓ fact-checked
Munchrd: Do octopuses dream, and do they practise hunting in their sleep?Nature

Do octopuses dream, and do they practise hunting in their sleep?

No one can confirm it. Octopuses have two sleep stages, and during 'active sleep' their skin flickers through colours, their…

✓ fact-checked
Munchrd: How do humpback whales cross an entire ocean without getting lost?Nature

How do humpback whales cross an entire ocean without getting lost?

The honest answer is that scientists are not sure. Humpbacks hold a remarkably straight course, deviating by less than one…

✓ fact-checked
Munchrd: What is the goblin shark, and why is it almost never seen alive?Nature

What is the goblin shark, and why is it almost never seen alive?

The goblin shark (Mitsukurina owstoni) is a rare, deep-sea shark and the only surviving member of a family about 125 million…

✓ fact-checked
Munchrd: Why are giant praying mantises suddenly spreading across Europe?Nature

Why are giant praying mantises suddenly spreading across Europe?

In 2026, two Asian mantis species, Hierodula tenuidentata (the giant Asian mantis) and Hierodula patellifera (the Indochina…

✓ fact-checked
Munchrd: How do fireflies glow?Nature

How do fireflies glow?

A firefly glows through bioluminescence, a chemical reaction in its abdomen where a molecule called luciferin reacts with…

✓ fact-checked
Munchrd: How do chameleons change colour?Nature

How do chameleons change colour?

Not by moving pigment around, and not mainly for camouflage. A chameleon changes colour by actively tuning a lattice of tiny…

✓ fact-checked
Munchrd: Why do bees die when they sting you?Nature

Why do bees die when they sting you?

A worker honeybee's sting is not a smooth needle but a barbed harpoon. In thick, elastic mammal skin the backward-facing…

✓ fact-checked
Munchrd: Why do cats always land on their feet?Nature

Why do cats always land on their feet?

Cats have an automatic righting reflex: their inner ear senses which way is down, and their flexible spine and…

✓ fact-checked
Munchrd: Why do whales beach themselves?Nature

Why do whales beach themselves?

There is rarely one answer. A single stranded whale is usually already sick, injured, old, or carrying parasites that…

✓ fact-checked
Munchrd: Why don't spiders stick to their own webs?Nature

Why don't spiders stick to their own webs?

Partly because not all the silk is sticky: an orb web's spokes and frame are dry threads the spider mostly walks on, and only…

✓ fact-checked
Munchrd: Why can you smell rain coming?Nature

Why can you smell rain coming?

You are smelling two different things. The earthy scent after rain is petrichor, driven by geosmin, a molecule made by soil…

✓ fact-checked
Munchrd: Why can't birds fly backwards?Nature

Why can't birds fly backwards?

A normal bird wing generates lift and thrust mainly on the downstroke and just recovers on the upstroke, so the push is…

✓ fact-checked
Munchrd: Why do animals go quiet in an eclipse?Nature

Why do animals go quiet in an eclipse?

Because the sudden darkness of totality looks exactly like nightfall, and most animals run their daily schedule off light,…

✓ fact-checked
Munchrd: Why do cats knead?Nature

Why do cats knead?

Kneading is a leftover from kittenhood: nursing kittens push against their mother to get milk flowing, and the motion stays…

✓ fact-checked
Munchrd: Why do dogs tilt their heads?Nature

Why do dogs tilt their heads?

Nobody is certain. The most likely explanations are that tilting helps a dog locate a sound or see your face past its muzzle,…

✓ fact-checked
Munchrd: Why do flamingos stand on one leg?Nature

Why do flamingos stand on one leg?

Mostly because it takes almost no effort. A flamingo's leg bones lock into a passive gravitational stay that holds the body…

✓ fact-checked
Munchrd: Why do meteor showers happen every year?Nature

Why do meteor showers happen every year?

Because Earth's orbit crosses the same streams of comet debris at the same point every year. A comet lays down a long trail…

✓ fact-checked
Munchrd: Why do wombats poop cubes?Nature

Why do wombats poop cubes?

The cube is shaped inside the intestine, not by the anus. In the last stretch of a wombat's very long gut, the wall has two…

✓ fact-checked
Munchrd: Why don't woodpeckers get concussion?Nature

Why don't woodpeckers get concussion?

They do not absorb the shock, and they do not need to. A 2022 study filmed woodpeckers and found the head and beak decelerate…

✓ fact-checked
Munchrd: Why is blood red?Nature

Why is blood red?

Blood is red because of haemoglobin, the oxygen-carrying protein packed inside red blood cells. Its haem group holds an iron…

✓ fact-checked
Munchrd: Why is the ocean salty?Nature

Why is the ocean salty?

The sea is salty because rain slowly dissolves the rock on land, and rivers carry those dissolved salts to the ocean. Water…

✓ fact-checked
Munchrd: Why is the sky blue?Nature

Why is the sky blue?

Sunlight is white, a mix of every colour. As it passes through the air, molecules of nitrogen and oxygen scatter the short,…

✓ fact-checked
Munchrd: Why do cats purr?Nature

Why do cats purr?

A cat purrs by rapidly twitching the muscles of its voice box, around 25 times a second, so the vocal folds snap together on…

✓ fact-checked
Munchrd: Why do leaves change colour in autumn?Nature

Why do leaves change colour in autumn?

A tree stops making chlorophyll and pulls the valuable bits (nitrogen and magnesium) back out of the leaf before dropping it.…

✓ fact-checked
Munchrd: Why do moths fly into lights?Nature

Why do moths fly into lights?

They are not actually attracted to it. A 2024 motion-capture study found flying insects tilt their back (dorsal side) toward…

✓ fact-checked
Munchrd: Why do onions make you cry?Nature

Why do onions make you cry?

Cutting an onion breaks cells that normally keep two ingredients apart. They mix, two enzymes fire in a chain, and the result…

✓ fact-checked
Munchrd: Why is the sea blue?Nature

Why is the sea blue?

Water is intrinsically blue. It gently absorbs red and orange light through the vibration of its own molecules, so once you…

✓ fact-checked
Munchrd: Why can wood frogs freeze solid and thaw alive?Nature

Why can wood frogs freeze solid and thaw alive?

Because the wood frog is freeze-tolerant: as ice starts to form, its liver dumps a flood of glucose that works like…

✓ fact-checked
Munchrd: Why do zebras have stripes?Nature

Why do zebras have stripes?

The leading explanation is that stripes are anti-fly wear. Zebras live where biting flies carry deadly diseases, and their…

✓ fact-checked
Munchrd: How do birds sense Earth's magnetic field?Nature

How do birds sense Earth's magnetic field?

Birds have a genuine magnetic compass, and the leading explanation is astonishing: a light-triggered, quantum chemical…

✓ fact-checked
Munchrd: Why did scientists just find things inside you that aren't quite alive?Nature

Why did scientists just find things inside you that aren't quite alive?

They're called obelisks: bare little loops of RNA, discovered in 2024, that live inside the microbes in your mouth and gut.…

✓ fact-checked
Munchrd: Why do thousands of starlings move as one?Nature

Why do thousands of starlings move as one?

Nobody is. A murmuration has no leader and no plan. Each starling just follows three tiny rules, stay close, match your…

✓ fact-checked
Munchrd: Why does fresh-cut grass smell so good?Nature

Why does fresh-cut grass smell so good?

That smell is a chemical wound response. When grass is cut, torn or bitten, it releases a burst of green leaf volatiles…

✓ fact-checked