I've heard the Czech surnames Hudáček and Chudáček (and Slovak Chudáčik) before, but never Hudáčik, nor can I find such a surname in the Czech or Slovak online phonebooks. Perhaps it is still Czech or Slovak, yet I just can't find it. Note, the Czech "ch" is a hard phlemy "h" sound, so it's possible there was a spelling change in your surname when your ancestors immigrated (this happened in my family as well).
Cindy, I'm 99.9% sure that your surname is Slavic in origin (the "-áček", "áčik" surnames invariably are). My first guess is that "hudacik is an English-corrupted spelling of the Slovak "Chudáčik." Note, the lands that are now the Czech Republic and Slovakia once belonged to the Austro-Hungarian Empire, as did a couple other Slavic nations, namely Croatia and Slovenia.
