Skip to Main Content

That Fresh Cut Grass Scent is Really a Signal of Distress

Spring is in the air! It’s time to mow the lawn and breathe in the smell of freshly cut grass. But this pleasant springtime scent may actually be a chemical cry for help. We explain how plants communicate, their chemical response to being damaged, and how bugs play a part.
Season 5 Episode 65 Length 03:10 Premiere: 05/14/19

Recent Episodes

Sponsored by:

Specials

Season 5 Episodes

How Do Antiviral Drugs Work?
S5 E99 Length 06:53 Premiere Date 05/11/20

The Early Plan to Fight COVID with the Polio Vaccine
S5 E98 Length 05:26 Premiere Date 05/01/20

Do Masks Stop COVID-19? (Yes! Here's Why)
S5 E97 Length 09:42 Premiere Date 04/17/20

How Did We Get COVID Vaccines So Quickly?
S5 E96 Length 05:37 Premiere Date 04/01/20

Can Soap Really "Kill" the Coronavirus?
S5 E95 Length 05:38 Premiere Date 03/18/20

The US Military Gave Out Shark Repellent For Years
S5 E94 Length 07:32 Premiere Date 01/10/20

Which of These Mushrooms Could Kill You?
S5 E93 Length 05:40 Premiere Date 12/23/19

11 Things You Can Do With Your Dead Body
S5 E92 Length 06:50 Premiere Date 12/18/19

Cartoon Chemistry!
S5 E91 Length 06:50 Premiere Date 12/13/19

How Miracle Berries Alter Your Taste Buds
S5 E90 Length 04:42 Premiere Date 12/04/19

Yule Log Chemistry Trivia - 4 Hours of Cozy Fireplace
S5 E89 Length 4:11:33 Premiere Date 12/02/19

Can You Cryogenically Freeze Your Body and Come Back to Life
S5 E88 Length 07:58 Premiere Date 11/27/19

The Science of J. Kenji López-Alt's Roasted Potato Recipe
S5 E87 Length 10:21 Premiere Date 11/22/19

World’s Deadliest (& Cutest) Animals
S5 E86 Length 08:42 Premiere Date 11/06/19

Where Did the Vampire Lore Come From?
S5 E85 Length 08:51 Premiere Date 10/31/19

How Do Blacksmiths Make Swords?
S5 E84 Length 05:11 Premiere Date 10/16/19

How to Make Magnetic Slime
S5 E83 Length 04:43 Premiere Date 10/09/19

Space Mirrors and Other Weird Ways to Fight Climate Change
S5 E82 Length 04:10 Premiere Date 09/25/19

We Tested Google’s Tips for Getting Stains Out
S5 E81 Length 16:02 Premiere Date 09/18/19

Is Superhero Strength Real?
S5 E80 Length 03:35 Premiere Date 09/10/19

How Much Does a Cloud Weigh?
S5 E79 Length 03:26 Premiere Date 09/05/19

Don't Mix These Things with Birth Control!
S5 E78 Length 05:30 Premiere Date 08/21/19

What Exactly Happened at Chernobyl?
S5 E77 Length 08:54 Premiere Date 08/15/19

Can a Fecal Transplant Save You From This Dangerous Bacteria
S5 E76 Length 04:16 Premiere Date 08/06/19

How Do We Fight the California Fires?
S5 E75 Length 06:26 Premiere Date 07/30/19

What Happens When You Overdose?
S5 E74 Length 05:42 Premiere Date 07/23/19

The Top 5 Strangest Poisons That Can Kill You
S5 E73 Length 04:48 Premiere Date 07/16/19

Can We Make Ocean Water Drinkable -- and Should We?
S5 E72 Length 04:13 Premiere Date 07/02/19

How Pee Helped Win the Revolutionary War (Maybe...)
S5 E71 Length 05:09 Premiere Date 06/25/19

What Does the Moon Smell Like?
S5 E70 Length 05:48 Premiere Date 06/19/19

What is Ringworm and How Do You Get Rid of It?
S5 E69 Length 04:11 Premiere Date 06/11/19

Could CBD Make You Fail a Drug Test?
S5 E68 Length 03:43 Premiere Date 06/04/19

What Causes Auroras?
S5 E67 Length 04:34 Premiere Date 05/29/19

Why is Carbon the Key to Life? (On Earth, Anyway)
S5 E66 Length 04:21 Premiere Date 05/21/19

That Fresh Cut Grass Scent is Really a Signal of Distress
S5 E65 Length 03:10 Premiere Date 05/14/19

How Do Pregnancy Tests Work?
S5 E64 Length 03:16 Premiere Date 05/07/19

How Does Pepper Spray Work?
S5 E63 Length 03:41 Premiere Date 05/01/19

How to Get Rid of Skunk Smell
S5 E62 Length 03:40 Premiere Date 04/23/19

How to Get Rid of Skunk Smell
S5 E62 Length 03:40 Premiere Date 04/23/19

Why Do Clothes Shrink in the Wash?
S5 E61 Length 04:15 Premiere Date 04/16/19

Why Do Clothes Shrink in the Wash?
S5 E61 Length 04:14 Premiere Date 04/16/19

White, Green, Black, and Oolong Tea: What's the Difference?
S5 E60 Length 04:32 Premiere Date 05/09/19

White, Green, Black, and Oolong Tea: What's the Difference?
S5 E60 Length 04:31 Premiere Date 04/09/19

Why Are Birds Different Colors?
S5 E59 Length 04:13 Premiere Date 04/02/19

Why Are Birds Different Colors?
S5 E59 Length 04:12 Premiere Date 04/02/19

These Two Women Changed Chemistry Forever
S5 E58 Length 04:59 Premiere Date 03/20/19

These Two Women Changed Chemistry Forever
S5 E58 Length 04:59 Premiere Date 03/20/19

Are We Running Out of Helium?
S5 E57 Length 04:35 Premiere Date 03/12/19

What's In Dog Food?
S5 E56 Length 05:37 Premiere Date 03/05/19

What's In Dog Food?
S5 E56 Length 05:37 Premiere Date 03/05/19

Can Mixing Cleaning Chemicals Kill You?
S5 E54 Length 04:30 Premiere Date 02/19/19

Can Mixing Cleaning Chemicals Kill You?
S5 E54 Length 04:30 Premiere Date 02/19/19

How Did the 80s Get Hair So Big?
S5 E53 Length 04:31 Premiere Date 02/12/19

The Perm
S5 E53 Length 04:24 Premiere Date 02/12/19

Is White Chocolate Actually White Chocolate?
S5 E52 Length 02:56 Premiere Date 02/05/19

Is White Chocolate Actually Chocolate?
S5 E52 Length 02:55 Premiere Date 02/05/19

Does Shaving Cream Do Anything?
S5 E51 Length 08:15 Premiere Date 01/30/19

Why Flamingos Are Pink and Hardcore
S5 E50 Length 03:32 Premiere Date 01/22/19

Why Flamingos Are Pink and HARDCORE
S5 E50 Length 03:32 Premiere Date 01/22/19

Citrus Scent DEBUNKED!
S5 E49 Length 03:48 Premiere Date 01/17/19

Citrus Scent DEBUNKED!
S5 E49 Length 03:48 Premiere Date 01/17/19

Can Plastic Be Composted?
S5 E48 Length 04:33 Premiere Date 01/09/19

Can Plastic Be Composted?
S5 E48 Length 04:32 Premiere Date 01/09/19

How Does Low-Dose Aspirin Work?
S5 E47 Length 04:27 Premiere Date 01/07/19

How Does Low-Dose Aspirin Work?
S5 E47 Length 04:27 Premiere Date 01/01/19

What Makes Kimchi So Delicious?
S5 E45 Length 04:39 Premiere Date 12/18/18

How is Kimchi Made?
S5 E45 Length 04:39 Premiere Date 12/18/18

Is Santa's Flame Resistant Suit Killing Him?
S5 E44 Length 03:53 Premiere Date 12/11/18

Is Santa's Flame Resistant Suit Killing Him?
S5 E44 Length 08:15 Premiere Date 12/11/18

Why Don’t Antarctic Fish Freeze to Death?
S5 E43 Length 04:11 Premiere Date 12/04/18

Why Don’t Antarctic Fish Freeze to Death?
S5 E43 Length 04:13 Premiere Date 12/04/18

Why Does Humidity Feel Gross?
S5 E42 Length 04:55 Premiere Date 11/27/18

Why Does Humidity Feel Gross?
S5 E42 Length 04:54 Premiere Date 11/27/18

How is Leather Made?
S5 E41 Length 04:03 Premiere Date 11/13/18

How is Leather Made?
S5 E41 Length 04:03 Premiere Date 11/13/18

Fact or Fiction: Uncooked Rice is Bad for Birds
S5 E40 Length 04:30 Premiere Date 11/06/18

Fact or Fiction: Uncooked Rice is Bad for Birds
S5 E40 Length 04:29 Premiere Date 11/06/18

Do Astronauts Need Sunscreen?
S5 E39 Length 05:03 Premiere Date 10/23/18

How Do You Catch Fruit Flies?
S5 E38 Length 03:16 Premiere Date 10/16/18

How Do You Catch Fruit Flies?
S5 E38 Length 03:16 Premiere Date 10/16/18

Tardigrades
S5 E37 Length 03:12 Premiere Date 10/09/18

Tardigrades
S5 E37 Length 03:11 Premiere Date 10/09/18

Turning the Boston Harbor into Actual Tea
S5 E36 Length 04:10 Premiere Date 10/02/18

How Much Tea Would it Take to Turn the Boston Harbor into It
S5 E36 Length 04:11 Premiere Date 10/02/18

What is Natto?
S5 E35 Length 04:46 Premiere Date 09/25/18

What is Natto?
S5 E35 Length 05:09 Premiere Date 09/25/18

Can Silver Nanoparticles Combat Your Stink?
S5 E34 Length 02:52 Premiere Date 09/18/18

Can Silver Nanoparticles Combat Your Stink?
S5 E34 Length 02:47 Premiere Date 09/18/18

What are Eye Boogers?
S5 E33 Length 01:47 Premiere Date 09/11/18

What are Eye Boogers?
S5 E33 Length 01:43 Premiere Date 09/11/18

How Does Double Acting Baking Powder... Doubly Act?
S5 E32 Length 02:23 Premiere Date 09/04/18

How Does Double Acting Baking Powder... Doubly Act?
S5 E32 Length 02:19 Premiere Date 09/04/18

How Plastic Recycling Actually Works
S5 E31 Length 03:01 Premiere Date 08/28/18

How Plastic Recycling Actually Works
S5 E31 Length 08:15 Premiere Date 08/28/18

Can You Take Expired Drugs?
S5 E30 Length 03:25 Premiere Date 08/21/18

Can You Take Expired Drugs?
S5 E30 Length 03:20 Premiere Date 08/21/18

Will This Pop a Balloon?
S5 E29 Length 08:11 Premiere Date 08/07/18

Will This Pop a Balloon?
S5 E29 Length 07:52 Premiere Date 08/07/18

Yellowstone and Their Steaming Acid Pools of Death
S5 E28 Length 02:59 Premiere Date 08/01/18

How Air Conditioning Works
S5 E27 Length 04:23 Premiere Date 07/23/18

How Air Conditioning Works
S5 E27 Length 04:35 Premiere Date 07/24/18

3 Most Useful Kitchen Gadgets - Are They Worth It?
S5 E26 Length 03:12 Premiere Date 06/17/18

Why Does Stinky Cheese Stink?
S5 E25 Length 04:57 Premiere Date 07/10/18

Why Does Stinky Cheese Stink?
S5 E25 Length 08:15 Premiere Date 07/10/18

Hydrangeas and the Science of Do-Overs
S5 E24 Length 04:10 Premiere Date 07/03/18

Hydrangeas and the Science of Do-Overs
S5 E24 Length 08:15 Premiere Date 07/03/18

Surströmming: The Secrets of this Stinky Swedish Fish
S5 E23 Length 07:54 Premiere Date 06/26/18

Surströmming: The Secrets of this Stinky Swedish Fish
S5 E23 Length 08:15 Premiere Date 06/26/18

How Do Hydrangeas Change Colors?
S5 E22 Length 05:05 Premiere Date 06/19/18

How Do Hydrangeas Change Colors?
S5 E22 Length 05:39 Premiere Date 06/19/18

Are We Breathing Caesar's Last Breath
S5 E21 Length 05:24 Premiere Date 06/12/18

Are We Breathing Caesar's Last Breath
S5 E21 Length 05:46 Premiere Date 06/12/18

How Seashells Are Made
S5 E20 Length 03:43 Premiere Date 06/05/18

How Seashells Are Made
S5 E20 Length 04:16 Premiere Date 06/05/18

The Ultimate Donut Battle: Cake vs. Yeast
S5 E19 Length 04:32 Premiere Date 05/29/18

The Ultimate Donut Battle: Cake vs. Yeast
S5 E19 Length 04:41 Premiere Date 05/29/18

Chameleons Are Masters of Nanotechnology
S5 E18 Length 03:48 Premiere Date 05/22/18

Chameleons Are Masters of Nanotechnology
S5 E18 Length 04:14 Premiere Date 05/22/18

How Milk Becomes Cheese
S5 E17 Length 06:44 Premiere Date 09/10/18

Does Melatonin Do Anything?
S5 E16 Length 04:22 Premiere Date 05/01/18

How Do Airbags Work?
S5 E15 Length 03:11 Premiere Date 05/01/18

Burning Ice from the Ocean Floor
S5 E14 Length 03:44 Premiere Date 09/10/18

Small Bottle, HUGE Fireball (How Flame Jetting Works)
S5 E13 Length 04:09 Premiere Date 04/17/18

Why Can’t You Buy Fresh Olives?
S5 E12 Length 03:15 Premiere Date 04/10/18

What's That After-Rain Smell Made Of?
S5 E11 Length 03:58 Premiere Date 09/10/18

The Half-Life of Uranium & Collecting Gold in Acid
S5 E10 Length 02:51 Premiere Date 09/10/18

How Do We Know the Half Life of Uranium?
S5 E10 Length 05:39 Premiere Date 03/27/18

Cow Burps Are Warming the Planet
S5 E9 Length 02:49 Premiere Date 09/10/18

Cow Burps Are Warming the Planet
S5 E9 Length 05:39 Premiere Date 03/20/18

What Are Century Eggs?
S5 E8 Length 02:52 Premiere Date 03/13/18

What Are Century Eggs?
S5 E8 Length 05:39 Premiere Date 03/13/18

TV Forensics: What Do CSIs Actually Do?
S5 E7 Length 04:16 Premiere Date 09/10/18

TV Forensics: What Do CSIs Actually Do?
S5 E7 Length 05:39 Premiere Date 03/06/18

Nose Blindness, Mouthwash, and Hand Sanitizer--Your Question
S5 E6 Length 02:24 Premiere Date 09/10/18

How to Make the Best Cheap Hot Cocoa Possible
S5 E5 Length 03:04 Premiere Date 02/20/18

How to Make the Best Cheap Hot Cocoa Possible
S5 E5 Length 05:39 Premiere Date 02/20/18

Chemtrails
S5 E4 Length 02:29 Premiere Date 02/06/18

Chemtrails
S5 E4 Length 05:39 Premiere Date 02/06/18

The Race to Invent the Periodic Table
S5 E3 Length 05:34 Premiere Date 01/30/18

Do Ketogenic Diets Really Work?
S5 E2 Length 05:39 Premiere Date 01/23/18

The Only Video You'll Ever Need to Watch About Gluten
S5 E1 Length 05:39 Premiere Date 01/16/18

See All Episodes

caret down

TV Schedules

Upcoming

No upcoming airdates

Recent

No recent airdates

Explore KET