Ladies and gentlemen, allow me to introduce the Glis Glis of Amersham!
"The Glis Glis is one of Britain's rarest introduced mammals living in the wild and resembles a small grey squirrel. For some reason it has established itself in the Chilterns (most densely around Chesham Bois) and nowhere else in the country.
Their nickname is the Seven Sleepers as they hibernate for seven months of the year. Walter Rothschild, who later became the second Baron Rothschild, brought the first six Glis Glis to England in 1902. No-one knows exactly why, but he turned them loose in Tring Park and they spread and bred! However, instead of happily hibernating out of doors they moved inside for the English winter! Soon, local farmers were complaining of apple stores being ruined and local people were hearing unexplained bumps in the night ... a sure sign that the Glis Glis were making themselves quite at home in the attic. One woman was convinced she was going mad!" -Amersham.org.uk