A sexually-frustrated female chimp has taken to smoking and spitting on visitors at the Zhengzhou Zoo.

Lui Bing, director of the zoo in the capital of central China's Henan Province, said 13-year-old Feili's inability to find a satisfactory mate has turned her from a "gentle girl" to a "shrew."

Lui said Feili's "husband" is now 41 years old and unable "to meet her sexual demands."

The zoo has tried to find another partner, but all have been rejected.

Feili regularly takes her frustrations out on the zoo's visitors.

A once happy and friendly animal, Feili now appears sullen in her cage, sleeping all the time and ignoring visitors - except when she spies a cigarette.

She then rushes to the front of her cage and becomes anxious and impatient when visitors ignore her requests for a cigarette.

A boy at the zoo said he watched Feili spit at a visitor standing four meters away from her cage.

"A tourist threw a cigarette butt to just outside the cage, she tried to get the butt with a stick," the boy said.

When bought from the zoo in Guangzhou, the capital of south China's Guangdong Province, she was gentle and obedient and often taken out of her cage for a walk.

Feili smokes because of curiosity rather than addiction, and she learned how to spit from badly-behaved visitors, Lui said.

"She is a real problem for the zoo," he said.