Russian pet shops are reporting a shortage of domestic rats, as shoppers snap them up ahead of the Chinese New Year - the Year of the Rat.
Shoppers are said to be buying even mice, hamsters or gerbils. But vets warn that some unwanted rats will be released in the streets.
While Russia's main religion is Christian Orthodox, Chinese astrology is a pastime for many.
Chinese New Year, based on the Moon's cycles, begins on 7 February this year.
Rats are soft, charming and clean and do not need a great deal of care, traders say.
But "not everyone is going to be delighted to get a real rat as a present, and those that can't house them will either return them to a shop, or release them in the streets," said one Moscow vet quoted by the AFP news agency.
In December customers hoping to buy rats formed long queues in pet shops in the northern city of Novgorod, Itar-Tass news agency reported.