Hippo sweat is red.
 

Hippos are most active at night.
 

 
 

Though not nocturnal, hippos tend to be most productive at night. This is partly due to the weather, as they’re native to Sub-Saharan Africa and spend most of the day submerged in water to keep cool. After leaving their resting waters at dusk, they’ll spend as many as five hours per night foraging for food, sometimes 2 to 3 miles away, and sleep on land. Grazing tends to be a solitary rather than communal affair, with the notable exception being mothers still caring for their calves, and the herd finds its way back to the water in the morning.