They gather in packs at night, usually just past dusk, and assemble behind buildings and alleyways. Empty bags in hand, they move at a steady pace, stalking large dumpsters and garbage cans for food, clothing and other treasures to be found. Often, they take home enough to sustain them for weeks on end.

Meet the freegans: a group of crusaders dedicated to saving the environment and saving money at the same time. They may have started as an underground community, but these days the group could include your next-door neighbor, roommate, or your boss. Their cost-cutting approach may be unconventional, but experts say it’s paying off and catching on.

“The whole idea of ‘green economics’ and cheap living has led to a renewed interest in freeganism,” says Jeff Ferrell, a professor of sociology at Texas Christian University and author of the book Empire of Scrounge. “It’s a great way to decrease harm on the environment while also keeping your costs down.”

What Is Freeganism?

A freegan is someone who avoids using money to acquire food and other goods. Spun out of the anti-globalization movement of the mid '90s, freeganism began as a reactionary lifestyle to consumerism, gluttony and greed. Freegans believed they could obtain food and other necessities for free, thereby avoiding big businesses and reducing their consumption of resources.

The word “freegan” takes its name from the word “vegan,” as members support a "cruelty-free” agenda that avoids meat and dairy. Today, freeganism also extends to non-vegetarians, as well as non-edible things like clothing, books and furniture.

Most freegans find things by dumpster diving or gathering outside a store and sorting through the trash. Others use a barter system to obtain goods and services, while some rely on collectives that promote the sharing of things like bicycles and cars.

Become a Freegan

If you want to do form your own group, Ferrell says it’s important to understand how your city works. “Before you go out, educate yourself about the rhythm and timing of your neighborhood,” he says. “Find out when the college dorms are being cleaned out, or when the donut shop throws out its food.”

Of course, a simple Google search (Stock Quote: GOOG) can connect you with freegan groups in your city.

New York resident Peter Lee always had bread to eat in college, thanks to the local sandwich shop. The shop baked fresh loaves daily, and whatever didn’t sell would be thrown out. Lee spoke to the manager and found out what time each day a new batch of bread was taken out. He would then head over to the shop and bring home all the bread from the day before. “It was basically day-old bread,” recalls Lee, “so it was still fresher than what we bought at the grocery store.”

Common Myths

Although most people would find the idea of foraging for items in a dumpster unsanitary and unsafe, Ferrell says it’s important to remember that grocery stores have plenty of reasons to throw away food that is perfectly fresh, clean and edible. Ferrell says he often takes home bags of oranges that are thrown out simply because one of the oranges was damaged. Other times, grocery stores are clearing their shelves to make room for a newer shipment of a product.

Will Parson, a San Diego-based photographer, became a freegan after documenting a group of dumpster divers in the city. He says it's easy to find sealed food with an expiration date that is months away. “I've found dozens of gallons of milk one night, and dozens of bags of chips another,” he says, adding: “The excessive packaging around many foods makes it very easy to pick them from the dumpster unscathed.”

Freegans aren’t limited to finding just food. Ferrell says he’s found tools, jewelry and money in the trash, thanks to people cleaning out their workspace or closets. Just the other day, he took home an antique crystal vase.

Another myth: Dumpster diving doesn’t really involve diving anymore. Ferrell says it’s easier to sort through boxes and garbage bags along the curb. But if he’s drawn to a particular dumpster, he’ll always bring along a long pole to help him reach what he wants. He notes that he always asks permission before sorting through someone’s trash. “Sometimes a homeowner will actually bring me other things from their house, once they find out what I’m doing,” he says.

Saving Money

Freeganism may have started as an anti-consumerist subculture, but these days, its principles can be applied to the general public.

“Once you get the hang of it, you can find just about anything in the dumpster,” says Parson, “so it's a good idea to think before buying something brand new that you might find used from a friend or discarded in the trash.”

“We’re like modern-day treasure hunters,” adds Ferrell. And as the saying goes, one man’s trash is another man's treasure.

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