They look tiny against the warheads strapped underneath them.
However, size hasn't mattered when reportedly taking out Russian tanks and entire groups of soldiers in one 140-kilometre-per-hour swoop.
Ukraine's "kamikaze" first person view (FPV) drones are the latest cheap and nasty nuisance causing a buzz on the battlefield — and across Russian social media.
While the use of unmanned aerial vehicles (UAV) has been ubiquitous since the start of Russia's invasion, their evolution continues to surprise — and often worry — countries closely watching from the sidelines.
FPV drones appeared several months ago, but have recently been gaining attention with footage circulating, claiming to show their growing impact and piles ready for swarms of attacks.
So what makes them unique, and what's the state of play in the game of drones for a possible spring offensive?
Cheaper, immersive and precise
Generally weighing no more than 500g, FPV drones have traditionally been used by hobbyists for racing.
Now — like most improvised drones popping up in Ukraine — they are being adapted and fitted with munitions.
Despite their small size, the racing drones can carry rocket-propelled grenades (RPGs) of up to 1kg and hone in on targets at high speeds for damaging, one-way "suicide" missions.
Costing less than $1,000, Ukrainians aren't worried about getting them back.
The popular US-made tactical Switchblade drone traditionally costs around $US8,000 ($12,000), while the DJI Mavic — which is commonly used as a loitering munition carrier — runs at just over $US2,000.
Ben Caves — the deputy director of defence and security at RAND Europe — said FPVs are the next evolution of battlefield drone technology.
"What you're seeing with these FPV drones is kind of an evolution in terms of ability, speed, capability and price, which is a really important factor," he told the ABC.
"These are more sort of a specialist Ferrari-type drone … designed to be fast and manoeuvrable."
Their range is limited to around 5km to 10km, but a defining capability is how they are controlled.
Pilots strap on goggles with a live-streamed camera feed from the drones, giving them a unique, immersive view.
This allows pilots to be more accurate, and to carry out surprise attacks in enclosed spaces or to loiter and wait for a target.
Small weapons, big targets
Various videos have been released, appearing to show dramatic FPV drone attacks.
In one, a drone is seen entering the doorway of a building occupied by Russian troops before exploding.
In footage from December, an FPV drone catches up to a fleeing Russian BMP infantry fighting vehicle and flies directly into the back doors.
Now, nearly weekly, Ukraine is releasing videos claiming to have taken out expensive equipment with its cheap kamikaze drone attacks.
Discussions have also been ramping-up on Russian Telegram channels about the impact of FPV drones.
According to military weapons expert Samuel Bendett, Russian military commentators have noted how quickly they moved to the foreground when six months ago attention was on commercial DJI quadcopters.
They added that the FPVs cost considerably less than Russia's Lancet loitering munition drones.
For months, Russia has been carrying out its own kamikaze-style attacks, using Iranian-made Shahed-136 drones.
They are packed with explosives and pre-programmed with a target's GPS coordinates, often striking key Ukrainian infrastructure.
While they are much larger and more powerful than Ukraine's FPV drones, they are also considerably more expensive and supply is difficult.
Countries such as Australia, the United States and Canada have placed a series of sanctions on suppliers of the Iranian drones to Russia.
Sarah Kreps — the director of the Cornell University Tech Policy Institute and former US Air Force officer — said the more-recent evolution has been the "constant flow" of Chinese-made DJI drones into Russia.
"These quadcopters can be reconnaissance, or even retrofitted for lethal strikes, but they're more commercially available and impossible to embargo," she told the ABC.
Rumoured stockpiles
Ukraine has been pushing to build its "army of drones", pledging to spend $US550 million on UAVs in 2023, with a focus on local supply deals.
Secretary of Ukraine's National Security and Defence Council Oleksiy Danilov has said acquiring kamikaze drones is among the country's top priorities.
In January, the government launched a campaign to raise additional funds for a fleet of 1,000 FPV drones, describing them as "a revolutionary combat tool".
That money is being raised through the Starlife-Charity foundation, which has helped Ukrainian forces since the start of Russia's invasion.
There are also several other organisations independently crowd-funding and developing the kamikaze drones.
Nastya Konfederat — who is involved in aerial reconnaissance and drone piloting for the Ukrainian military — said mass production would change the situation on the frontlines.
"Just FPVs with a payload can stop the enemy's offensive," she said in a video for Starlife.
"We want large-scale and centralised donation and development efforts.
"We can scale this technology. We will deliver thousands of strikes from places they do not expect."
A pro-Russian blogger last week posted claims that Ukraine had already bought up almost the entire market of FPV drone components in China.
He said more than 50,000 drones were stockpiled for a series of swarm attacks.
The post has been viewed more than 2 million times and attracted hundreds of comments.
Last month, an unverified video also did the rounds on social media apparently showing a stockpile of hundreds of the racing drones for Ukraine.
Analysts say it's difficult to verify the claims and exact numbers.
However, it is likely that Ukraine is accessing large quantities of the parts and developing the drones quickly, Mr Caves said.
"I saw a statistic somewhere where, if you look at the civilian industry, there's something like 100,000 being manufactured a month, globally," he said.
"The fact that these are really, really inexpensive items — and as [the Ukrainians] get better and better at manufacturing them — they will be able to scale up."
He said limitations laid with the number of pilots who can be trained to launch swarm attacks.
"You're not going to have 1,000 Ukrainian drone operators, but they might have quite a few hundred," Mr Caves said.
"So you couldn't necessarily have a 1,000-drone flyover, but what you could do is have 10 to 20 that go in, wave after wave, after wave, until you've completely destroyed the target."
Can they be stopped?
Anti-drone technology is evolving as fast as UAVs themselves.
"Anti-drone technology has been the holy grail since the beginning of the war," Professor Kreps said.
Most drone systems can be jammed, so both sides are continuously experimenting with different types of jamming technologies.
In addition to developing its own anti-jamming systems, Professor Kreps said the US and Israel, in particular, have been developing and sending anti-drone technologies to Ukraine.
Russian media last week reported that the country's new Serp-VS5 anti-drone system had passed tests and was ready for deployment.
It has the capability to jam signals and detect intruder drones across a span of 360 degrees, within a 5km range, according to state news agency TASS.
The report came after a series of incidents involving drones being downed, or conducting attacks, in Russian territory, which Moscow has blamed on Ukraine.
Reportedly, the drones involved were larger, combat drones.
When it comes to defending against swarms of kamikaze drone strikes, it's all a game of numbers.
As Ukraine has learned with Russia's kamikaze drone onslaughts, you can down 85 per cent, but it only takes a handful to get through to cause significant damage.
The speed and size of FPV drones makes them even trickier to target when launched en masse.
"With the FPVs the Ukrainians might be launching in numbers if there's a spring counter-offensive, they're moving at a much faster pace, are more agile, they're smaller, and they're able to loiter and change direction," Mr Caves said.
The next 'worrying' evolution
The FPV drones are showing what may be possible with the advancement of artificial intelligence (AI).
The Russian military commentators on Telegram this week highlighted that the swarm potential of the kamikaze drones made it "quite obvious that the future belongs to robotic, unmanned technologies", predicting it may be possible within 10 to 15 years.
Mr Caves said the big game-changer would be when these types of cheap, semi-autonomous drones further evolve and humans are removed from combat decision-making.
"I think that's something that's worrying a lot of countries, including the US."
Ethical implications arise when you take "humans out of the kill chain", especially in situations like drone swarms, which are already difficult to defend against.
"Imagine you get to a situation where you've got AI swarms of drones making their own decisions about what they choose to target and not target and there's no human making that decision," Mr Caves said.
"As you start to see the technology development, there will be an arms race where certain nations will press ahead with technology which removes more and more of the human element of making an ethical decision."
Professor Kreps said that, even now, ethics needed to be central to discussions around drone usage, but it was just not keeping up.
"We're still just starting to wrap our heads around the type of updating we need to do," she said.
"But, at the least, we need to be aware that the previous criticisms about ethical or legal use, just are not terribly relevant in this new context."
