From the BBC news website
There's a bit more information on page 179 of the 422 page (and 8MB) PDF file of abstracts from the 25th meeting of the Bioelectromagnetics society, but not a lot more.
edited to fix links
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.
There's a bit more information on page 179 of the 422 page (and 8MB) PDF file of abstracts from the 25th meeting of the Bioelectromagnetics society, but not a lot more.
edited to fix links