Mice can 'foretell earthquakes'

By Dr David Whitehouse
BBC News Online science editor

Japanese researchers have observed mice behaving strangely after being exposed to electric and magnetic fields similar to those sometimes detected before earthquakes.

They became agitated and lost sleep

The levels of exposure were far smaller than humans are capable of perceiving.

Professor Takeshi Yagi of Osaka University says he first noticed the unusual behaviour in mice in his laboratory eight years ago, the day before the Kobe earthquake.

The agitation seen in the mice before the earthquake was reproduced by subjecting them to fluctuating electromagnetic fields suggesting the animals could be used as a crude way to predict earthquakes.

However, biologists point out that unusual behaviour in mice is difficult to define which may limit the usefulness of the technique.

Jumping fish

There are many anecdotal stories about animals behaving oddly just before earthquakes.

In China, catfish are said to sometimes throw themselves out of their tanks; in Mexico snakes are said to leave their burrows.

In the United States one retired worker from the US Geological Survey claimed to be able to predict earthquakes by counting the number of lost pet adverts in newspapers.

He said that in the two weeks before an earthquake, more pets wandered off than usual.

Disrupted clock

In Professor Yagi's experiments, mice were kept for two weeks in a stable environment so that their day-night rhythms could be monitored.

They were then exposed to low-intensity electromagnetic pulses for 30 minutes.

There are many reports of fluctuations in the Earth's electromagnetic field prior to an earthquake.

In a paper presented to a recent meeting of the Bioelectromagnetic Society (Bems), Professor Yagi says the electromagnetic pulses disrupted the internal "clock" of his mice, causing them to rest less often.

He says more experiments are needed to solidify the results but, he believes the work to be the first experimental evidence showing animals' ability to sense imminent earthquakes.