No, they are not aliens, but they are possibly in your mouth right now. Eeew!!!
Taken by scanning electron microscope (SEM), these images may urge you to clean your teeth thoroughly tonight, or even send you for another dental appointment ASAP.
The magnified photos showing these plague-forming bacteria, plague on teeth, and a cavity due to accumulated food debris, aim to let people really see the microorganisms lurking on our teeth and pay more attention to teeth cleaning.