After being stung by complaints, Taiwanese officials have traced the mysterious yellow gunk that has splattered cars and laundry for weeks to a seasonal influx of bees, and their droppings.

Bees attracted to farms and plant nurseries near the densely-populated city of Kaohsiung have smothered a neighbourhood with their droppings since February, alarming and irritating residents who could not figure out where the mess was coming from.

Chen Kung-fu, a vice section chief with the municipal environmental protection unit, said an investigation was launched into the matter after residents complained of splodges on almost every parked car as well as clothes left outside to dry.

The bee count should decline in April after flower season, Mr Chen said, but until then, there is nothing the authorities can do to divert the insects away from homes.

"Bees are hard to stop because of their flight speed," added Mr Chen said. "But the faces can't hurt people. We can confirm that."

Widespread urban development in wildlife rich Taiwan has pushed into the island's farms and sub-tropical forests, making human contact with flora and fauna common.