Ant wrote to mention an ABC News article indicating that hampsters feel the same effects during the winter months as humans do. Known as Seasonal Affective Disorder (S.A.D.), winter-related depression affects up to 20 percent of Americans. From the article: "For example, if the animals spend more time hovering near the walls of their containers, rather than at the center, it's believed they feel more anxious. If they decline to slurp up tempting offers of sugar water, scientists take it as a sign of depression. Another test involves placing the animals in water and seeing if they swim or simply give up and float. Hamsters don't sink apparently, but float in water. 'The sooner they give up in the water, the more depressed they are,' Pyter said. 'If you give them an antidepressant they don't give up as quickly.'"