Yes, they were behind glass, whew!
I just had to google this one, the name was intriguing. From Wikipedia (use your own judgement as to quality of the information).
"'Fire-bellied' is derived from the brightly coloured red- or yellow-and-black patterns on the toads' ventral regions, which act as aposematic coloration, a warning to predators of the toads' reputedly foul taste. The other parts of the toads' skins are green or dark brown. When confronted with a potential predator, these toads commonly engage in an Unkenreflex, "Unken" being the plural form of "Unke", German for for firebellied toad. In the Unkenreflex, the toad arches its back, raising its front and back legs to display the aposematic coloration of its ventral side."
Gotta say, that is rather interesting! And, the rest of the article was too!