Hippos eat at night and sleep during the day.
The hippos usually sleep right after they finish their breakfast. Since the hippos sleep all day in cold water, they need a good layer of insulation to avoid hypothermia. In captivity, hippos do not get the exercise that they would in the wild since they don't have to look for their own food. Therefore, we carefully monitor how much they eat to keep them at a healthy weight. Sometimes they sleep right up against the edge of the pool or right outside the doors to their barn where it is difficult to see them.