The reason the monkey in the cage in the previous picture is pissed off is because here we see some wild monkeys at the zoo doing the "We're on the out-siiiiiiiide, you're on the in-siiiiiiiiide" dance in front of him. Just think how much it would piss you off to be a monkey in a zoo in a country where wild monkeys are as common as squirrels in Canada. The wild monkeys seemed to enjoy teasing the hell out of the caged monkeys by dancing about in front of their cage as well as running up, reaching through the bars and stealing their food. These wild monkeys were obviously ass-monkeys. As an anthropology major it was interesting for me to observe that the Jerk-gene predates the human species. Monkeys can be so cruel.