Goats, sheep maintain land in some Philly suburbs. Yes, you herd that correctly.

Paul Leonard keeps a tin pail and a cowbell in the bed of his pickup truck. And on days when his schedule allows, he points the vehicle toward the work site of some of Upper Dublin Township's most active seasonal contractors.

And they come running when they see him, if for nothing more than a handful of kibble.

For six years now, Upper Dublin has been employing a few dozen Katahdin sheep to help maintain rocky storm water basins on municipal property. As a lawn care strategy, it's a decision rooted in concerns about saving both manpower and the Earth.

And it's one that in the last few years has become increasingly popular in suburban municipalities — putting sheep, goats and other grazing livestock to work eliminating invasive plants and other vegetation from properties that are difficult, sometimes impractical, for two-legged workers to access.

"It really came out of having a discussion regarding our carbon footprint, and our overall expenses associated with property maintenance," said Leonard, the township's manager. "Upper Dublin has 600 acres of land, and we had to make decisions about how much attention we give to each property. One option was to do less maintenance. Another option was to use sheep."

Upper Dublin's herd usually spends about four months circulating among properties in the county, Leonard said. They're on loan from Susan Sacks' farm, a plot of family land about 40 minutes north in Perkiomenville.

Sacks, the assistant director of the Center for Sustainable Communities at Temple University's Ambler campus, said Leonard originally called her, asking for goats, more common in the commercial-grazing industry. But Katahdin are an unusually hardy breed, she said, ones that grow hair instead of wool and were originally bred to maintain land around power lines in the wilds of Maine.

"They're made for being outside," Sacks said. "And they end up being assets to these basins: They're aerating the ground as they're eating as opposed to lawnmowers that impact ground, making runoff worse."

And to make the deal even sweeter, it's not costing Upper Dublin anything to borrow the sheep. They thrive outdoors without any shelter, and aside from a few refills of their water trough each week, the sheep are pretty much left to their own devices.

Across the region, about an hour away from Leonard and his township's stormwater basins, a massive herd of about 100 sheep and goats thrives amid piles of municipal garbage.

The Lanchester Landfill in Narvon, a collection point for the Chester County Solid Waste Authority, is home to the animals, who have free reign of the property's 500 acres, according to David Horne, the waste authority's superintendent. They graze during daylight hours, providing a constant, if not substantial, aid in clearing patches of land.

"Environmentally, I like to think we're being good neighbors," Horne said on a recent tour of the property. "We have sheep and goats all around us. And when people hear that they're here, they're supportive. It's a matter of reflecting what the community is concerned about."

Dan Russell, the director of parks and recreation in Upper Merion Township, knows well how useful livestock can be.

In 2014, Russell and his colleagues struggled with how to clear fallen trees from an area of Bob White Park overgrown with vines, poison ivy and similar plants.

"The whole area was overrun," he said. "We looked at the possibility of clearing it with machinery, herbicide or a combination of both, and it was just extremely expensive."

Two years later, the area was clear, at a cost about $100,000 less than the most generous landscaper estimate, according to Russell.

The answer? Goats, about 20 of them that tore through the plants that most humans would balk at, in an area rendered impassible to heavy equipment.

At the time, the township turned to an outfit out of upstate New York to obtain its goats. But if the same project was commissioned today, Russell wouldn't have to cast his bid that far afield.

Brian Knox, the owner of the Maryland-based Eco Goats, said he's seen a bevy of new grazing services open up in the last five years. His closest competition used to be north of New York City or beyond the southern borders of Shenandoah National Park.

Now, he directs potential clients to farms in Delaware and Pennsylvania, including a few in the state's southeast corner.

Previously, Knox's animals were a staple in the Philly region. His herd helped trim Japanese mountain weed from a steep slope in Millbourne several times, an area where herbicide would've leeched into nearby Cobbs Creek. Another group made the trek up to Haverford College in 2013, where facilities director Don Campbell said they were vital in clearing space along the school's nature trail.

And they helped jump-start a trend that's survived today in West Laurel Hill Cemetery, where goats spend the summer months keeping weeds at bay in the cemetery's green burial area, a section where people are interred without chemicals.

But as Kristen Weber explains, goats and sheep aren't a perfect fit for every landscaping job.

"Sometimes, people think this will cost $100 and work better than Roundup," said Weber, who owns Amazing Grazing with her husband, Bruce, in southern Chester County. "Or that when you're done, the area will look like a golf course."

Instead, Weber said, she tells prospective customers to expect goats to act as a "first phase," clearing away brush or dangerous plants.

"You can't tell a goat to 'stay in this one area,'" she said. "We fence them in and allow them to trim away."

The Webers started their company in 2015, cresting the wave of new grazing operations that Knox observed. Their primary business, she said, is homeowners in their part of the state, in the rolling hills on the edge of Amish country.

Their latest customers are the Thomson family, who brought about 19 goats to their property in Glenmoore to deal with about a decade's worth of thorny weeds and vines.

"Before they came, I couldn't even see over to the next house," Kim Thomson said recently, gesturing to the property line near where the goats were penned.

Thomson's son heard about commercial grazing through a program on public radio. And when he ran across Bruce Weber's truck at a gas station, he knew he'd found a solution for his parents' overgrown yard.

When the goats arrived, a fallen tree limb was covered by a mound of poison ivy about eight feet wide and close to six feet tall. A day later, it was all gone.

"We're beyond pleased with this," Thomson said. "There's no way we could've cleared this ourselves."