Dozens of flights were disrupted at New York's John F Kennedy Airport - by turtles looking for somewhere to lay their eggs.
About 150 turtles in search of beaches crawled on to the tarmac forcing controllers to move flights to another runway, reports the Mirror.
Several pilots, some of them stifling chuckles, began reporting turtles on Runway 4L just as the morning rush-hour was beginning.
"We ceded to Mother Nature," said Ron Marsico, a spokesman for the Port Authority of New York and New Jersey, which owns the airport.
Workers had to scoop up the turtles and move them across the airport, he said. Flight delays averaged about 30 minutes.
"We are trying to help wildlife out a bit here," Mr Marsico said. "We built on the area where they were nesting for generations, so we feel incumbent to help them along the way."
The migration of diamondback terrapin turtles happens every year at John F Kennedy International Airport, which is built on the edge of Jamaica Bay.
In late June or early July the animals heave themselves out of the bay and head towards a beach to lay their eggs.