Why do we yawn?

Yawning photo by ytang3 @ flickr

Yawning photo by ytang3 @ flickr

What is the purpose of a yawn? We all do it on a near daily basis, most often when we least expect it. Yawning doesn’t take conscious effort, most of the time. Some people even think it’s contagious!

When we yawn no matter when or where we take in large gulps of air. So whats the purpose of this involuntary respiratory reflex? Well…the answer is we don’t know totally.

A few of the popular explanations are:

  • Yawning is our bodies way of regulating CO2 (carbon dioxide) levels.  When carbon dioxide blood gas levels reach a certain level our body will yawn in an attempt to increase the level of oxygen. A yawn is a large inhalation of air, and a slow exhalation. The longer the exhalation the better our body can strip the oxygen from the air, and exhale out carbon dioxide.
  • We yawn when we are tired, or bored. Yawning may be a way for your body to outwardly signal to you and others that you are ready to go to sleep. If you had been talking with Joe and it was late and Joe yawned, you would most likely finish up your conversation and let Joe go home and sleep right? Most of us would. The same thing with boredom. If you are giving a lecture on a subject and your students are yawning, that’s a good sign that what you are presenting to the class in not very interesting.

Is yawning really contagious?
Well, maybe…and maybe not. It is likely that when someone else yawns you yourself realise how tired you are and your body yawns as well. It is also possible that when someone yawns because their bodies level of co2 is low, and yours may be as well.

If you want to post comments or questions please do so below.

Why do dogs eat grass?

Photo from bobmarley753 @ Flickr

Photo from bobmarley753 @ Flickr

If you’ve ever had a dog, or ever seen a dog outside then you’ve most likely seen them eating grass amongst other things. Well why do all dogs eat grass, and poop? What’s the purpose of this universal seemingly strange behavior?

There are 2 trains of thought the 1st one being the most likely answer.

1. Dogs are hunters and scavengers. They used to forage for food, as well as hunt small game. Their natural diet would have consisted of both meats and naturally growing organic matter like grass, berries, and fruit. The animals they did catch and eat where herbivores and so they would contain plant nutrients that the dog would then ingest as well.

Dog’s who aren’t getting enough nutrients from their food or who just crave greens, may seek nutrients in other material like grass, or feces.

Dogs that eat these items however,  are not necessarily missing nutrients from their diet, it may be just a simple instinctive action.

2. Some people believe that dogs eat grass when they are sick to their stomach’s. Eating to much grass often causes the dog to regurgitate its stomach contents, and therefore relieves the dog.

Why do cops eat donuts?

Why do cops eat Donuts?

Here is a good question, donuts and cops, why are they associated. Why do cops eat donuts anyway? Well the answer might be a bit more simple than you may expect, at least that’s what my research tells me.


While being a cop can be cool at times, most of the time it involves sitting in a car and searching for bad guys or crimes in some shape or form.  Cops also work all hours of the day, and because of this the cops working at night need a place to get good coffee so they can be alert, and not fall a sleep on the job.

So where can cops get coffee 24hrs? Most Duncan Donuts are open 24hrs, and besides coffee they serve (you guessed it) donuts. Who can resist a donut, with their coffee. They are cheap, and packed with sugar.

Of course you can get coffee at convenient stores, and again most convenient stores have donuts or other sugar filled pastries to go with that coffee. Cops also tend to spend time at convenient stores as they tend to be located at intersections, contain people loitering, drunks, and other such high profile people.

Then again it could just be a funny stereotype.

Why do dogs eat Grass?
Why do dogs eat Poop?