A male lab mouse, genetically identical to ones found to sing, is shown, Monday, Oct. 31, 2005, at Washington University School of Medicine in St. Louis. Researchers say mice may be added to the short list of creatures that sing in the presence of the opposite sex, including songbirds, humpback whales, porpoises, insects and, possibly, bats.

BEIJING, Nov. 2 -- Scientists have known for decades that male lab mice produce high-frequency sounds ¡ª undetectable by human ears ¡ª when they pick up the scent of a female mouse. This high-pitched babble is presumably for courtship, although scientists are not certain.

    But it turns out those sounds are more complex and interesting than previously thought, according to an AP report. 

    "It soon became ... apparent that these vocalizations were not random twitterings but songs," said researcher Timothy Holy." There was a pattern to them. They sounded a lot like bird songs

    To make their point, the researchers provided audio recordings of the sounds, which have been modified for human ears. The recordings do indeed sound birdlike.

    The findings by the researchers at Washington University School of Medicine in St. Louis are published online Tuesday in the journal Public Library of Science Biology.

    If the analysis by the researchers is confirmed, mice can be added to the short list of creatures that sing in the presence of the opposite sex, including songbirds, humpback whales, porpoises, insects and, possibly, bats.

    "There was joy in this discovery," Holy said. "We didn't expect it."

    The finding opens the possibility of using mice to study and develop treatments for autism and other communication disorders, said Holy, the lead author and assistant professor of neurobiology and anatomy at the university's medical school.

    Bird song, how it is perceived and learned, is used to understand how the human brain works. But some questions might be posed better with mice, for experimental convenience, he said.

(Source: China Daily/AP)