Going Ape At The Zoo

I spent this past Saturday afternoon at the Denver Zoo, and focused on photographing the primates, since the temperature was almost 80 degrees and many of them were out and about.  Of course, when I say out and about, I mean in their respective compounds.  I still l don't see why the zoo can't just let all the animals roam free in a large park-like setting, just like in the wild.  The zoo visitors could roam around just like they would if they were in the jungle.  If one of the animals decides to snack on a hyena, or possibly a Californian, the zoo could simply have one of their employees shoot it with a dart gun, and take it to a "time out" area for the rest of the day.  And no thanks necessary for the idea, Denver Zoo.