Thousands of bees found a new home on the wing of a Delta flight which was headed from Pittsburgh to New York.

The flight was delayed for 20 minutes as authorities waited for experts to come and carefully remove the bees from the wing. According to ABC affiliate WTAE-TV in Pittsburgh, a professional bee keeper was called to remove the bees. The group of bees formed on the wing while the aircraft was getting refueled. Master beekeeper Stephen Repasky, who reportedly was called to remove the bees, said that the bees are a protected species that cannot legally be killed.

"When a colony of honeybees swarms, its nature's way of dividing on a large scale," Repasky told reporters. "So, the old queen takes off with half the colony and they go looking for a new place to set up residence."

Curious passengers eagerly snapped pictures of the strange event. 

This was not the first time a colony of bees have swarmed an aircraft. Repasky said the recent event was the fourth time he'd been called to the airport this year to take care of a swarm of honey bees.

Airport spokesperson told ABC News that among another three incidents two swarms were removed in May and one in June, both from equipment but not planes.