Jack Hanna's Animals Go Wild, Take Over 'Late Show With David Letterman' (VIDEO)

With most late night shows following a pretty strict unwritten formula, things can seem fairly predictable most of the time. That's why it's always a lot of fun when animals get introduced into the mix. They simply will not follow expected protocols, and that very unpredictability makes for some brilliant spontaneous television, as with Jack Hanna's latest trip to "Late Show" (Weeknights, 11:35 p.m. EST on CBS.

The animals he brought along, as usual, took over the set. While David Letterman was clearly amused at the honey badger pumping -- or humping -- the floor to mark his territory, he was less enthused after a river otter bit Hanna. The animal apparently got the digit confused with chicken.

But right after it happened, Letterman stood up. "If you guys are gonna be all right, I have some paperwork I need to finish upstairs," he quipped. "Turn off the lights when you're done."

To emphasize the value and importance of preserving wildlife, Hanna brought out an endangered jaguar, which made itself at home on Letterman's desk and took quite a liking to his microphone. "A lot of 'em die from eating microphones," Letterman quipped.

Never scripted and always fun to watch, animals are a late night tradition that may make hosts squeamish or uncomfortable -- all the more fun for the home audience -- but still make for some of the most honest and genuine moments on television.

Watch "Late Show" every weeknight at 11:35 p.m. EST on CBS.

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