According to a zoo spokeswoman, Gingrich was nipped during a behind-the-scenes tour with two Magellanic penguins, one of whom went after Gingrich's finger.

Gingrich has made zoo stops a regular occurrence during his nationwide campaign. While spending time in Des Moines, Iowa, Gingrich carved out time to visit an 85-year-old tortoise at a local zoo. The former House Speaker made a similar pit stop while fundraising in San Diego and expressed frustration when a planned Election Day visit to the Birmingham, Ala., zoo was canceled. According to the AP, Gingrich claims to have visited more than 100 zoos in his lifetime.

Gingrich has spoken previously about how as a child, he dreamt of growing up to become a zoologist. He said a visit to a battlefield when he was 14 changed his mind, orienting him instead toward public service.

In fact, Gingrich's first foray into public life might have been zoo-related. The AP reported that Gingrich worked to start a zoo as a child in his hometown of Harrisburg, Pa.

Gingrich was in St. Louis ahead of planned remarks at a meeting of the National Rife Association.