Angry Rhino Experiencing Constipation

So we went to SF zoo today. Had an awesome time checking out the animals (most don't really belong to US). It's really strange that we didn't find any California wild animals or North American this/that. Almost all the animals were either imported from Africa or Australia.

Anyway, we were extremely lucky because the animals weren't sleeping but out playing actively. I've posted a video of this rhino by himself in his "penthouse". He was trying to run down the door to the indoor area but too bad, the zoo authority must have predicted his destructive or you can call it his rude behavior (he doesn't have a habit of knocking on the door) that a thick metal bar was built to prevent damages. Look closely and you can see some signs of his "knocking", the door has some big holes on it. I didn't capture this on a video, so just use your imagination a little. A rhino, some holes and some freaked out zoo keepers! :P