Roofing is already pretty risky work, but add 50,000 bees to the mix and you’ve got a recipe for danger.

According to a news release from the Calderdale Council — located in West Yorkshire, England — roofers have been replacing the aging roof tiles of the Elland Library as part of a $2.26 million (£1.75 million) renovation project. As the roofers worked on the replacement job, they uncovered a large honeybee nest under the tiles.

“The contractors working to replace the roof as part of our refurbishment of Elland Library, had a real surprise when they discovered thousands of bees and a huge nest amongst the rafters,” said Calderdale Council’s Leader, Councilor Tim Swift.

An estimated 45,000 to 50,000 bees inhabited the hive, which took up a 10-foot by 4-foot space in the roof. Obviously, the bees had to go in order to finish the project, but the Calderdale Council didn’t wish to destroy them. Instead, they contacted Crest Pest Control and local honey suppliers Joyce Jones to safety remove the hive.

“We know how important it is to protect this precious species and so we contacted local experts to ensure the bees were safely and carefully rehomed,” Swift said.

It took beekeepers seven hours to remove the bees along with 110 pounds (50 kilograms) of honey and comb. The bees were successfully rehomed, meaning work on the roof could finally resume.

“The removal process wasn’t an easy task, as the bees clearly felt at home in Elland Library, but I’m pleased they’re now safely rehomed in hives in Norland,” Swift said.

The new roof, now free of bees, will include energy efficient panels. Work on the building began in late February, but had to be paused due to COVID-19 lockdowns. Work resumed in June and is expected to be completed in the spring.