No, Senator, there is no evidence that nicotine is addictive.

From the Associated Press:

Zoo tries to get smoking chimpanzee to kick habit
Associated Press
August 26, 2005 CHIMP0827

XI'AN, China — The handlers of a smoking chimpanzee in a zoo in northwest China are trying to get her to kick the habit.

The 26-year-old female chimpanzee has been smoking for 15 years. Her mate died recently, which caused her to smoke even more.

Now, the chimp's keepers are worried about her health as a result of her intense smoking. So, they're trying to give her milk instead of cigarettes.

She started smoking years ago by picking up butts from tourists.