A group of people watches three albino rats leap from small baskets into a big cage at an indoor hall in the Argentine capital. It’s Ratapalooza, an annual event held on Sunday in Buenos Aires, promoting the adoption of rodents raised in animal facilities or used for research in science labs that are no longer wanted. To attract adoptive families, Team Ratas, which is Spanish for rats, organizes the Ratapalooza as a bit of a fair, complete with stalls selling keychains, mugs, stickers and hair clips in the shape of rats and mice. The money raised goes to veterinary and food expenses for the rodents, which they foster at home before putting them up for adoption.