As thousands of people wait at Camp Idomeni, idling for days without any clue when they may be allowed to cross the border, frayed nerves and desperation are showing everywhere.
One young man, convinced he is being cheated of his place in line, starts an argument with an older man carrying a child on his shoulders.
Nearby, a group of around 100 people are sitting on the railtracks to block a cargo train traveling from Macedonia toward Greece, chanting, "Open the border!" and "We want to pass!"
Further up the queue, a boy of 10 is screaming in a tearful rage.
The migrants arrive from dawn until after sunset. They walk along a road before they cut across 2 kilometres of fields to the camp, which is located next to the railtrack.
The crowd only grows larger as few are allowed to pass through the narrow, sliding metal gate that leads to a more comfortable and hopeful reception camp in Macedonia, only 500 metres away.
"We're concerned with this pressure building up here," UNHCR spokesman Baber Baloch tells dpa. "People arrive hoping that the border will be open, but that doesn't seem to be the case."
According to the UN refugee agency, only 400 were allowed to pass to Macedonia on Wednesday.
"Greek authorities are working on four locations close-by which would have more than 8,000 capacity, so this population can be moved from here and enter the asylum seeking procedure," Baloch says.
There are no clear guidelines on who may or may not pass, Baloch says, adding, "We see some being returned after being allowed to pass."
People directly in front of the gate sit on the ground following police orders. They are quiet, except when police let someone jump the queue, such as a pregnant woman with children or a sick person.
But even those unfit for a long wait might be told to go to the back of the line.
"I wait 8, 9 days," says Samir Shari, a disabled man from Aleppo. He is in a good mood after reaching the gate area with his daughter.
"We want to go to Germania. It goes very slowly," Shari says in broken English.
Behind him, a tent measuring roughly 5 by 10 metres is packed with people who make up the next section of the queue. They are narrowly squeezed together, but they refuse to leave their spots, even when police at the gate end their shifts and leave until the next morning.
Zahary and Mulham, two men in their twenties from Aleppo, peer out from between the tent's walls at a corner to blow smoke into the air as they share a thin rolled cigarette.
"We spent the night here," Mulham says. "No food, no water, no air. We are not leaving until we go through."
Virtually all of the people in the camp are Syrians and Iraqis, who are split into Arabs and Kurds.
Among them is Darwin Ali, a 37-year-old Iraqi Kurd. He is a sound engineer and speaks five languages, including English, Arabic, Kurdish, Farsi and Greek. His linguistic skills make him a favourite with the police whenever tensions escalate among those in the queue.
Ali's skills give him access to areas around the gate that are usually off-limits to refugees, but even he has to wait his turn.
"We are stuck here with my wife and son for eight days," Ali says. He says that he hopes to make it to Germany to find a job and complete a masters programme in audio engineering.
Idomeni is the hardest part of his family's 25-day trip from Iraq, he says, worse even than the dinghy crossing from Turkey to the Greek island of Lesbos.
"We're left to wait here in the cold and in bad weather," Ali says. "I regret it mostly because of my little boy."
His 3-year-old son is named Steve, "in honour of Steve Jobs," he adds.
Yet, while the situations is bad for Ali and his family, it is worse for others.
Countries on the Balkan route are now allowing only Syrians and Iraqis to pass. Others are stopped and have no right to assistance in many of the camps.
"Eight days we're here. We can't register, can't get food or shelter, like animals," says a young Pakistani man, who is sitting on the railtracks with three compatriots and two Afghans.
"We will wait here a few more days if the border opens," he says. "If not, we will go back to Athens."
The Pakistani man calls the conditions at the Idomeni camp "incompatible with human life", unfit "even for animals."
His friends do not want to go all the way back home, but they are also reluctant to return to Athens. "In that Greek place, they no like Pakistani, no like Afghans," one of them says.
"I am Pakistani ... No camp, no blanket, no food."