The mules go door to door collecting rubbish, but only if it has been properly separated. A mule can carry 150kg, but driver Francesco says he never loads them up that much because he loves his animals.
In many parts of the world, the sound of dirty bin lorries piercing the tranquillity of residential neighbourhoods is a familiar nuisance.
But in one hilltop town in Italy, the softer, gentler sound of the hooves of mules clip-clopping on cobblestones heralds the imminent collection of rubbish.
And by going back to traditional methods of waste collection, the town of Artena has also been able to better sort and manage its waste.
At trash time in Artena, 40 kilometres south of Rome in the Lazio region, there's no noise of a reversing garbage track, and no loud shouts between workers as they go.
Instead, 27-year-old mule driver Francesco Bucci and his loyal steeds go quietly about their task.
Artena is a town of around 14,000, and claims to have the biggest pedestrianised historic centre for its size in Europe.
It also has a proud record in waste collection, especially in the old town, where the mule waste collection service operates. Here, separated waste collection carried out on the back of mules reaches 86 per cent of households.
That collection figure compares favourably to the national number of 55.5% of the Italian population, according to a 2018 report by Italy's ISPRA (National Institute for Environmental Protection and Research).
Only the northern provinces of Treviso and Mantua had a higher figure than the old town of Artena.
Felicetto Angelini, the local mayor, is proud of the achievement.
"Separate garbage collection in Artena started in 2017 and as a forced choice, we've had to resort to the help of an animal that has accompanied us since the beginning of time. Artena exists thanks to mules, and now they also ensure day-to-day separate waste collection," he says.
He adds the mules have helped residents improve their sorting of their garbage.
"The result has been extraordinary, because almost immediately, within a couple of months, we have reached a percentage between 70 and 86 per cent. Here in the historical centre, it is now at 85-86 per cent."
Making life better
Around 1,000 people in the old town of Artena are benefiting from the mule waste collection service.
The door-to-door mule collection service also allows a new form of social contact, which many locals are enthusiastic about.
"Very good. Very very good. Yes, because we have solved the problem of having to walk to the garbage dumpster. Now instead, Francesco comes by and collects garbage on our doorstep. It's great," says shopkeeper Pina Angelini.
Others who live in the old town add that the mule service has meant they've got better at working out how to sort their waste.
"Francesco is great. On some occasions he leaves behind the garbage that is not supposed to be collected that day, and rightly so, because if it is the day of compostable, that's what you have to hand out," says 84-year-old Anna Maria Talone.
The bond between humans and mules in Artena is centuries old. Historically, mules were essential for transporting everything from food to building materials, furniture and timber along the laneways of the old town, which is perched atop a 420-metre limestone ridge. Now, four mules help with the garbage run: Mela, Mora, Rosciola and Pastora.
But it's not all bucolic idyll: Francesco Bucci concedes the work has its difficulties.
"The problem is that it is very difficult to walk around town. You have to be fit to be able to do it every day. You have to get up every morning at four o'clock and do the round. The town is big, I usually walk almost 20 kilometres a day, up and down. You need to be constant. But it is rewarding, the collection rate skyrocketed and the fact that people speak well of us… this is everything," he says.
And while a mule can carry up to 150 kilograms, Bucci says he never loads them up that much because he loves his animals.