Twelve office workers in Beijing were in the habit of turning off the air conditioning on hot days to avoid disturbing a pair of gray pigeons who were nesting under an outdoor air-conditioning unit.

Li Yong, the worker who first found the birds, said he was about to switch on the air conditioner one hot day when he saw two eggs in a nest under the unit.

"Later my colleagues and I saw two pigeons come to the nest and we realized they were incubating eggs there," Li said.

"So we decided not to use the air conditioner to keep quiet for the birds."

Now, two baby birds have hatched and the office workers are feeding and protecting them.