Zoo signs are important for informal learning, but their effect on visitor perception of animals has been sparsely studied. Other studies have established the importance of informal learning in American society; this study discusses zoo signs in the context of such learning. Through the lens of Critical Theory framed by informal learning, and by applying critical discourse analysis, I discovered subtle institutional power on zoo signs. This may influence visitors through dominant ideological discursive formations and emergent discourse objects, adding to the paradox of "saving" wild animals while simultaneously oppressing them. Signs covering a variety of species from two different United States-accredited zoos were analyzed. Critical Theory looks to emancipate oppressed human populations; here I apply it zoo animals. As physical emancipation is not practical, I define emancipation in the sociological sense--in this case, freedom from silence. Through this research, perhaps we can find a way to represent animals as living beings who have their own lives and voices, by presenting them honestly, with care and compassion.