Atheism and Anti-Theism same thing?

[God of Mr. Hanky]

Can an atheist identify as an anti-theist?

Sure he can, but not necessarily. If you are an atheist and you believe that tolerance of religious activity and the teaching of unfalsifiable ideas is better than campaigning to replace religious ideas with an interest in critical reasoning and inspiration through scientific achievement, then you aren't an anti-theist. Having been raised religious by some of the dumbest people on the planet, I understand first-hand the problems of the "live and let others fuck childrens' minds" mindset.