User blog:Sasha Dawg/That's Strange... Is This a Glitch?

I am currently making a bridge over the underworld so that I can fight the WoF easier (I have not yet entered hard-mode ever) and I don't care how it looks, so I'm making it out of anything and everything I have. One part of it is ebonstone, and after using a lot of it, corrupt zone monsters are spawning in the Underworld. Is this supposed to happen, or am I getting a glitch? I would like to know O_O