CLOSE
Original image
iStock

Why Do I Sometimes Get 'Brain Freeze' From Eating Ice Cream?

Original image
iStock

WHY? is our attempt to answer all the questions every little kid asks. Do you have a question? Send it to why@mentalfloss.com.

Have you ever eaten ice cream too fast on a hot day and ended up with a bad headache? That’s sometimes called a brain freeze. It doesn’t mean that your brain is frozen, though. It just means your body and brain are trying to figure out what to do about all that icy cold stuff you just swallowed.

Touch your tongue to the top, or roof, of your mouth and slide it back toward your throat. You have a lot of nerves there that pick up sensations like touch or temperature and send messages to the brain about them. When very cold things touch that part of the mouth, it’s kind of a shock to your body. Some scientists think one of the important nerves there goes a little crazy with the cold and starts sending lots of messages to the brain. But the brain reads those messages as pain instead of cold. Another idea is that the cold makes more blood flow to the brain. That causes your blood vessels to expand, or get bigger. Before you have a chance to say “Brrrrr!” you get a brain freeze.

That extra blood means more pressure in the brain. Some scientists think that may be the reason people feel like they have a headache. Your body reacts by making the blood vessels contract (get narrow) to try to lower the pressure. Once that happens, the headache usually goes away pretty fast. Not everyone gets brain freezes, and scientists aren’t sure why. If you do get them, don’t worry. Brain freeze headaches aren’t dangerous. But next time, don’t eat your ice cream so fast!

Did you know that cats seem to get brain freeze too? Take a look


Original image
iStock/Chloe Effron
Why Do I Get Cavities?
Original image
iStock/Chloe Effron

WHY? is our attempt to answer all the questions every little kid asks. Do you have a question? Send it to why@mentalfloss.com.

Your mouth is a busy place. There are hundreds of different kinds of bacteria living on your teeth, tongue and gums. Bacteria, as you may know, are tiny little critters that can only be seen with a microscope. We need some of them to help keep us healthy. Others are more of a pain—especially when they cause cavities (CAA-vih-teez), or little holes in our teeth. If you get a cavity, a dentist will have to treat it. You may get a filling.

During the day, you put all kinds of food into your mouth. When you eat, the bacteria that live in there eat, too. Some bacteria make acid out of the sugar in food. So when you eat sweet stuff—candy, cookies, and sugary drinks—you are helping bacteria to make more acid. The acid eats through the enamel, or the hard coating on your teeth. Over time, this can cause cavities and infections. Ouch! Luckily your spit, or saliva (suh-LIE-vuh), has minerals in it, like calcium and phosphate, that fight back by making your tooth enamel stronger and cutting down on acid. The fluoride in toothpaste helps do this, too. If you have a cavity, a dentist can fill the hole to keep bacteria from getting in and causing a bad infection. Unfortunately, there’s another reason for cavities that you don’t control: genes (jeenz).

Genes are little codes inside our cells that get passed down from our parents. They are instructions to our bodies that affect how we look, act, and grow. Genes may play a big part in whether we get cavities. Some people end up with cavities because of their genes, even if they take really good care of their teeth. Other people hardly get any. We can’t change our genes, but we can control other things. Brushing your teeth, visiting the dentist, and avoiding sweets can all help you keep cavities away.

Want to find out more about what lives inside your mouth? Watch the cartoon below from the National Institutes of Health.

 

Original image
iStock/Chloe Effron
Why Do Lizards Lose Their Tails and Regrow New Ones?
Original image
iStock/Chloe Effron

WHY? is our attempt to answer all the questions every little kid asks. Do you have a question? Send it to why@mentalfloss.com.

Many species of lizard lose their tails when they are being chased. When a predator (PREH-duh-tor)—an animal that wants to eat them, like a bird or cat—grabs for the tail, it falls off, and the lizard can run away. How does it happen? Scientists looking at geckos (a type of lizard) under a microscope have found out that some parts of the tail are weaker than other parts.

It’s no accident. The sections of a lizard’s tail will hold together until the lizard is in danger. Scientists think that’s when special cells inside the tail make chemicals that attack the weak points. Then—surprise!—the tail breaks off. It will also keep wiggling for a while to distract the predator while the lizard speeds off. Pretty awesome! That’s not the end of the story, either. Most lizard species can also grow a new tail. 

Lizard tails have a lot of jobs to do. Lizards move their tails around to “talk” to each other. It’s a kind of secret lizard language. The tail also helps lizards keep their balance when they’re scrambling up a tree or jumping from rock to rock. So even though losing the tail is a useful trick, growing it back is pretty important, too. Sometimes lizards can get carried away, though: one busy lizard from Argentina grew six new tails at once!

Watch a gecko regrow its tail in this video

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios