Blog Posts by Mother Nature Network (mnn.com)

By Laura Moss, Mother Nature Network

Although it's easy to assume that cats purr because they're content, research shows that purring is likely a means of communication and a form of self-healing.

Yes, your feline friend purrs when you stroke her fur, but cats also purr when they're frightened or feel threatened, such as during a visit to the veterinarian.

Veterinarian Kelly Morgan equates this reaction with smiling. "People will smile when they're nervous, when they want something, and when they're happy, so perhaps the purr can also be an appeasing gesture," Morgan told WebMD.

A cat's purr begins in its brain. A repetitive neural oscillator sends messages to the laryngeal muscles, causing them to twitch at a rate of 25 to 150 vibrations per second. This causes the vocal cords to separate when the cat inhales and exhales, producing a purr.

But not all cats can purr. Domestic cats, some wild cats and their relatives - civets, genets and mongooses - purr, and even

By John Platt, Mother Nature Network

It starts with Earth Day on April 22. What follows every spring and summer is a calendar jam-packed with eco-themed and animal rights holidays. But where do these special days come from? Who creates them and why? Do they all serve good causes, or are some of them just for fun? Sometimes you need to dig to find the answers - but knowing the story behind the occasion can help you to know which ones are worth celebrating.

Government-supported holidays
Like Labor Day or Thanksgiving, some eco-holidays are established by government decree, often after being initiated by a private group or organization. Take Global Tiger Day (July 29) for example. One of the newer eco-themed holidays on the calendar, Global Tiger Day was first proposed in 2010 by the 13 nations where tigers still exist and was created to promote awareness about tiger conservation. The governments of Russia, India, Bangladesh and other nations officially recognized the day,

By Judd Handler, Mother Nature Network

It's common for some women over 40 to experience a sputtering sex drive, sluggish metabolism, lethargic energy levels, fluctuating moods and other cruel machinations of the aging process.

But life after 40 doesn't have to be left to Mother Nature's fate. Consider getting plenty of exercise, modifying your diet and taking these seven best supplements for women over 40:

1. Strontium: Women over 40 with a family history that includes osteoporosis, or risk factors associated with bone loss should take 340 mg a day of this mineral, says Jacob Teitelbaum, MD, medical director of the national Fibromyalgia and Fatigue Centers. "Strontium has been shown to be almost twice as effective as osteoporosis medications in improving bone density - without the side effects," Teitelbaum says. A study in the New England Journal of Medicine concluded that postmenopausal women who supplemented with strontium increased bone mineral density of the lumbar

Obama drinking beer
by Michael d'Estries, The Mother Nature Network

For brewers on both sides of the political aisle, the release this weekend of the official recipe for "White House Honey Ale" offered a rare moment of bipartisan "Cheers!"

Since the middle of August, beer enthusiasts have been pressuring the Administration to release the "secret recipe" via signatures on the official White House site and a more formal Freedom of Information Act request.

"In keeping with the brewing traditions of the founding fathers, homebrewers across America call on the Obama administration to release the recipe for the White House home brew so that it may be enjoyed by all," the petition reads.

While the Obama Administration has been enjoying the White House Honey Ale (incidentally, the first beer ever brewed within the White House) since the 2011 Super Bowl, interest over the beverage did not erupt publicly until the President brought some with him on the campaign trail this summer.

"I think I've only tried the

By Chanie Kirschner, Mother Nature Network

Popcorn

What's a movie without popcorn? Turns out that the only reason the dynamic duo came to be was because they both rose in popularity at the same time. In the late 1800s, the portable popcorn machine was invented, about the same time as the motion picture. As movies became increasingly popular, vendors would set up shop wherever there was a crowd (even outside of a movie theater), and popcorn soon became a favorite American snack. It wasn't until the Great Depression set in that theaters themselves started to sell popcorn, desperate to make a buck (or even a penny) and draw struggling Americans inside. Indeed, concession stands account for 40 percent of a theater's revenue these days, and a theater wouldn't be complete without a popcorn machine. So much so that the phenomenon created by theaters was transferred to home entertainment. A trip to Blockbuster (remember the good ol' days of Blockbuster?) wouldn't be complete without a box of

By Sidney Stevens, Mother Nature Network

Ready to work.

Our pets bring us joy and enrich our lives. But they can also bring joy and enrich the lives of others - with a little help from us. Whether your BFF is a dog, cat, parakeet or something more exotic, teaming up as a volunteer duo is a great way to share time with each other and share your combined gifts with the world. Here are some ways you and your furry (or feathery) friend can begin reaching out to others.

1. Donating blood
It's a regular ritual for many of us - the bloodmobile comes around, and we roll up our sleeves to give blood for the injured and sick. Well, it turns out animals need blood transfusions too, and for all the same reasons as humans. Good news: Now your pet can give the gift of life just like you do. To find a pet blood bank near you (donations are mainly from dogs and cats), ask your veterinarian or check this list from the Association for Veterinary Hematology and Transfusion Medicine.

2.

By Melissa Breyer, Mother Nature Network

Potato chipsIt's often hard to imagine simpler times - a world without computers, mobile phones, or a million flavors of potato chips. Back in the chip's humble 19th-century beginning, it was seasoned simply with salt and remained mostly unmolested until the 1950s. That's when Joe "Spud" Murphy, the owner of Irish chip company Tayto, developed the technology to add flavor to chips during the manufacturing process. Murphy created the world's first seasoned chips, Cheese & Onion and Salt & Vinegar, and there's been no looking back since. Case in point? The following...

1. Tako Octopus Flavored Chips
Although shaped more fishlike than cephalopod, these funky snacks from Nong Shim are described by the company as "Round & cute octopus-shaped (joyful to the eye); tasty & salty; and smell of octopus." Reviewers describe them as strange, fishy, octopus-like and ... addictive!

2. Walkers Cajun Squirrel
What the huh? Squirrel? Those zany

By Sidney Stevens, Mother Nature Network Dirt dinner?

Call them antiquated. Call them crazy. But science is finding that many natural practices - things humans used to do but gradually gave up as modern technology and urban living took hold - are actually good for us. These practices take advantage of our evolutionary design and help our bodies work the way they're supposed to. Sometimes you just can't improve on Mother Nature.

1. Eating dirt
Most of us spend considerable time trying to eliminate dirt from our lives, but evidence suggests it might be time to rethink things. Dining on dirt and clay - geophagy - not only seems to soothe the stomach but may also eliminate bad bacteria, viruses, fungi and toxins from the gut. Animals as well as people in tribal and rural societies (particularly pregnant women and young children) have been doing it since the dawn of time. In fact, dirt eating is culturally sanctioned and even encouraged in many parts of the world.

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