The Emperor Penguins would disagree- https://en.wikipedia.org/wiki/Wildlife_of_Antarctica

They've been lucky the area's too cold for Black Rats from ship wrecks to survive and decimate their colonies, as has happened to many birds on many islands and remote peninsulas.

Neither does Lord Howe Island, but continental Antarctica is probably the world's largest rat-free region. I'm sure many rats have made it ashore, and survived briefly, and some have managed to live in stations/bases, but most of the continent will be rat-free.

On the other hand, I'm aware rats have managed to survived in South Georgia, and caused problems for local flora and fauna there.