A family of beekeepers were horrified to discover they had been robbed of 40 hives, holding a total of one million bees.
The Manton family, who run the business Beekeeper Honey, discovered the brazen theft on Saturday (24 February).
The hives, which stood in a farmer's field between Fringford and Bicester in Oxfordshire, contained around 25,000 bees each.
In total around one million bees are believed to have been taken, sometime between 17 and 24 February.
Beekeeper Lara Manton, who runs the company, said her parents discovered the hives had gone missing while carrying out a winter inspection to check they had not been damaged by the cold weather.
"They were in a field between Fringford and Bicester, which you can't see from the road," Manton told the Oxford Mail. "So it is weird, someone must have scouted them out or knew they were there. That's what worries us."
She described the theft as "really sad" but said it would not negatively impact the business financially.
"It is not going to shut down our business. But for others that could be half of their whole operation. I just worry it will become a regular occurrence," she said.
"I was meant to manage these bees for my first season, so they were my bees which is really sad," Manton added.
She expressed concern that whoever has taken the bees may not have the knowledge to properly look after them.
Ged Marshall, chairman of the Bee Farmers Association, told The Telegraph that he had never heard of a theft on this scale before.
"Others I have heard of have only ever been in single figures," he said.
"The puzzling thing is how the thieves knew they were there to start with. To find the site which is hidden away, you either must have been following someone for weeks or deliberately searching for the hives," Marshall added.
Thames Valley Police is investigating the incident and has urged anyone with information about the theft to call 101.