A plague of crows has descended on the northeast city of Shenyang, darkening the daylight sky, occupying the balconies of apartment blocks and showering shops and pedestrians with droppings. The Beijing Youth Daily described how more than 10,000 of the birds had settled in the city this winter, bringing misfortune and inconvenience to its six million citizens. 'Daytime is like a cloud of crows,' said one resident. 'Look at the sky and you see several thousand. There must be more than 10,000. 'Where do they come from? We do not know. They drop their excrement on our heads. In the evenings, it is like rain, it is hard to avoid. It is very inconvenient.' An official of the city's sanitation department said that each day its staff had to clean at least 50kg of the droppings. People are being forced to wear hats and face masks and cover their shoes to protect themselves. The birds are not only having an impact on residents, but also on businesses. Thousands have moved into Zhonghua Street, one of the main shopping districts. A famous bread shop that used to be at its busiest at 5pm is now almost idle at that time because the shop windows are covered with crow droppings. A housewife said each night she used to go to the balcony of her apartment and drive away the crows sitting there. 'They are very smart. As soon as you go back into the apartment, they come back. If you stay on the balcony, they hover in the air and shower you with droppings. I have given up the fight against them,' the housewife said. Street cleaners use recordings of sirens to drive them away, but with limited effect. 'There is nothing we can do. Some people use firecrackers but it does not help much. No one knows what to do,' the housewife said. Wang Zhifeng, assistant to the chief of the Shenyang Wild Animal Protection Station, has been studying the problem for two years. He said the migration of the birds into the city was a result of its outward expansion into surrounding areas, which had led to the felling of trees and the loss of their natural habitat. It is also a result of the building of more parks and green space within the city, making a more comfortable environment for the birds. Crows are a bad omen for Chinese, signifying misfortune, evil and corruption. During the past two years, Shenyang has witnessed one of the biggest corruption cases in China, with a dozen senior members of the city Government, including the former mayor and a vice-mayor, sentenced to death or long prison terms.