You can also meet them on Sixam and invite them to move in.
With the EP installed, Aliens may be lurking around town in disguise. These extraterrestrials hail from the planet Sixam, which is a secret lot in the Expansion Pack. The Sims 4 Get to Work features the new Alien life state.
The Sims 4 Aliens (Get to Work) Abductions, Male Pregnancy, and Brain Powers A UFO Abducts a Sim in The Sims 4 Get to Work This great shot of a UFO was provided by snackrafice on our Forum.