Commuters stopped in their tracks as the swarm filled the air in Greenwich Church Street, close to Greenwich market, on Tuesday evening.
Many shared videos of the unusual scene on social media, while Transport for London posted a photograph of the bees resting on traffic lights.
Abigail Hering, who runs a nearby jewellery shop, described the swarm as “absolutely crazy”.
She said she could initially hear an “underlying hum”, adding: “It was just literally swarming, above the cars around the one-way system.”
The swarm stayed for at least an hour, with onlookers shocked at the “hideous” sight, she said.
Ms Hering said: “Millions of them on the traffic lights. And then at that point they’d come lower so they were actually buzzing around the people.
“And while I was videoing them I looked down and I could see literally the front of me covered in bees.
“They were on me. They were on everybody. They were in your hair, on your top.”
The swarm later subsided after beekeeper Phil Clarkson and his wife Tracey used a mobile hive to collect many of the insects.
Mr Clarkson, who placed the mobile hive on top of his car, said the swarm possibly came from Greenwich Park.
He said: “Nobody was stung here today.
“People did get a bit nervous, and they were quite concerned understandably.
“But then when we talked to people and explained to them that actually a swarm is very benign, the likelihood of getting stung is very, very rare, and in most cases it’s only when people swat them or squash them on their body that the bee will sting them.
“They’re very calm and very docile when they’re swarming.”
Asked about how common a swarm of this kind is, Mr Clarkson said: “At this time of the year it’s quite common, but it is rare to get them to land on such things as traffic lights.”
A law is being prepared to set the tempo at which the ballad should be played and sung, with consequences for those who put the anthem in a “damaging situation”.
Concerns have been growing that the patriotic number, called March Of The Volunteers, is “not universally respected and cherished”.
State media has reported on recent “chaos” where people have laughed as the song was played, with others making a ruckus.
“Due to a lack of legal constraints, the national anthem is casually used and sung in an unsolemn manner,” the Xinhua news agency claimed.
China already has laws restricting the use of its national flag and national emblem, but aside from a ban in adverts there are no laws protecting the national anthem.
In 2014, Beijing set out regulations which allowed the song to only be used during major sporting events and formal diplomatic occasions – making the anthem off limits to various forms of “private entertainment”.
Written in 1935, March Of The Volunteers was officially adopted as China’s national anthem in 1982.
The buoyant, military-minded song calls on the Chinese people to “arise” and “march on” towards the establishment of a new nation.
The draft bill is expected to be submitted for its first reading next month.
Officers arrived at Ashwaubenon High School in Green Bay, Wisconsin, after a parent called to say they had seen someone walking through a back door carrying a bag and wearing what looked like body armour and a mask.
Students were evacuated and another nearby school was placed on lockdown as armed officers searched the area.
But the alert ended when officers realised the suspected assailant was a child who had dressed up for Star Wars Day – an annual celebration observed by fans of the sci-fi franchise.
Police captain Jody Crocker said the parent was right to call the emergency services.
He said: “The saying ‘If you see something, say something’ certainly applies to this and we always encourage people to report suspicious activity.
“The outfit actually looked like he wearing a bullet-proof vest or a flak jacket.
“Coupled with wearing that mask and walking into the back door of the school (it) made a person very concerned.”
The new product is apparently aimed at those with plenty of cash, as the retailer pockets a cool $425 (£330) for each pair.
The firm’s website describes the jeans as typifying ‘rugged, Americana workwear’ and ‘hard-working action… that shows you’re not afraid to get down and dirty’.
Some reviewers, however, have not given them a clean bill of health, including the host of TV show Dirty Jobs, Mike Rowe.
“Finally – a pair of jeans that look like they have been worn by someone with a dirty job… made for people who don’t. And you can have your very own pair for just $425,” Rowe wrote in a Facebook post that was shared thousands of times.
“The Barracuda Straight Leg Jeans aren’t pants. They’re not even fashion. They’re a costume for wealthy people who see work as ironic – not iconic.”
Another review wrote: “This is a joke, right? Do you also sell jeans covered in cow manure? Oh, that must be the deluxe model.”
But not everyone was so dismissive.
“What’s the beef about buying mud jeans?” one commentator said on Twitter. “If someone can afford $400 for a pair of dirty jeans, so what? Go for it!”
The chain is no stranger to pushing fashion boundaries, launching jeans with ‘knee windows’ last month – but for a far cheaper $95 (£74).
If you fancy giving the idea a leg-up by investing in a pair, beware of the strict cleaning instructions – machine wash cold, line dry only.
The document was discovered in the West Sussex Record Office in Chichester, where staff had been unaware of its significance.
The original Declaration proclaimed the first 13 colonies free from British rule and was signed in Philadelphia on 4 July, 1776 – now America’s Independence Day.
Harvard University researchers Emily Sneff and Danielle Allen made the discovery while compiling records for a database.
It began in August 2015, when they stumbled on a simple one-line entry in the office’s catalogue: “Manuscript copy, on parchment, of the Declaration in Congress of the thirteen United States of America.”
They thought it would probably be a 19th century reproduction – but it turned out to be a “big mystery” and far more significant than they imagined.
Now christened the ‘Sussex Declaration’, it measures the same size as the original, 24in by 30in, but has been written horizontally.
It also does away with the state by state signature groupings of the original, and all the names are written by a single clerk.
The researchers discovered it was deposited along with other papers by the so-called “Radical Duke”, the Third Duke of Richmond, Charles Lennox.
He earned his nickname because of his support for the Americans during the revolution.
Exactly when and why it came to England is still unknown.
“While the parchment may have moved to the UK in the 1780s or 1790s, when the Third Duke could have received it, it is also possible that it moved to the UK only after 1836,” the researchers said.
The mystery could deepen as text appears to have been scraped away at the top of the document.
Hyper-spectral imaging is planned in conjunction with the British Library in the hope of revealing what was written.
Supreme Court Justice James Wilson, one of six people to sign both the US Constitution and the Declaration, is believed to be the most likely person behind the copy.
Professor Allen added: “This one was produced a decade later (than the original) with the signed parchment as its source, as part of the fight between federalists and anti-federalists about whether the new republic was founded on the authority of a single, united sovereign people or on the authority of 13 separate state governments.
“The federalists were making the first argument and this document appears to have been produced to support their case.
“It illuminates the politics of the 1780s in a flash.”