No, but beliefs about the afterlife aren't part of what defines an atheist. Atheists can disbelieve in any deities, and still believe in an afterlife (although of necessity, there would have to be a naturalistic explanation / cause for it).

That said, in practice, since most atheists have a considered position that is a side effect of critical thinking, most do not subscribe to an afterlife. If you don't afford belief to the unsubstantiated then in addition to not believing in gods, if you're logically consistent, you don't believe in the supernatural, afterlives, leprechauns, unicorns, ghosts, etc.

But athiests ARE humans, and humans are not exactly known for being logically consistent.

Nope, how I see it is you don't remember anything before birth, no pain,no hate no sadness just darkness, then why be scared to go back to nothing after you die. This is your Ownly life so live it the best now because you will never get another chance..