The Swedes may be warm, but they are not warm and fuzzy. This fall, authorities rounded up 3,000 wild rabbits and then burned them for fuel at a heating plant in central Sweden. Bunny-killing is an annual practice in Stockholm — it's used to combat overpopulation in the city's extensive network of parks — but the animals had never been used to heat buildings before this year. "The bodies contain a lot of fat, and fat has exactly the same energy content as normal heating oil," explained Leo Virta, chief executive of Konvex, the company handling the bunny-burning. Supporters said that since the bunnies were going to be culled anyway, using them for fuel was both economical and environmentally friendly. Unsurprisingly, Swedish animal-rights activists were not convinced.