We were at the zoo a couple of weekends ago. The hippos were quite frisky. There were three of them and they kept leaping from the water and wrangling with their jaws. A fair amount of water jumping and cavorting was also observed. In all of my visits to our local zoo I have never seen the hippos do anything but pose, half submerged in their pond. I also noticed the sign, the sign that said no rescue attempts would be made for persons falling into the hippo area. They are big, yes, jaws fierce, yes, they seem so docile, no. An adult hippo weighs approximately 7,000 pounds, the mother hippos often have to guard their young and keep them in the water because the fathers will not attempt to eat the young hippos when they are water bound, and a hippo can snap a full-grown crocodile in half with one bite of it's massive jaws. No wonder nobody would be willing to mount a rescue effort.