He was seen swimming back and forth in a figure eight pattern, again and again, for up to 12 hours a day.[1] Such behavior in captive animals usually points to boredom and stress.[10] The zoo hired an animal behavioral therapist at a cost of $25,000 to determine the reason for Gus' obsessive swimming.[3] According to the therapist, "Gus is just bored and mildly crazy in the way that a lot of people are in New York".[3] He ordered an "enrichment program" for the polar bear that included a redesigned habitat, "challenges" at mealtime, new toys and "positive-reinforcement training sessions".[2][3] In 2002 the BBC reported that zookeepers had installed a jacuzzi to "cheer up" Gus.[11] Gus was also the first zoo animal in history to be treated with Prozac.[6][7] After a few months, Gus' obsessive swimming tapered off, but never disappeared entirely.[3] He and his two partners, Lily and Ida, were featured at the 2005 International Conference on Environmental Enrichment.[12]