The FIFA World Cup is just days away, and the excitement isn't limited to football fans. At Brookfield Zoo in Chicago, animals are getting into the spirit of the tournament with soccer-themed enrichment activities. From American bison and Grevy's zebras to red river hogs and Addax, the animals have been kicking, nudging and chasing giant footballs as part of activities designed to encourage natural behaviours, physical exercise and mental stimulation. Here's a look at the zoo's adorable World Cup warm-up.