Alien abduction
Alien abduction is an event that can happen in The Sims, The Sims 2 and The Sims Bustin' Out when a Sim stargazes at night through a telescope. Their motives go haywire whilst they are on board the craft, and they return a few hours later.
The Sims
In The Sims, an abductee will simply return with a different personality.
The Sims 2
In The Sims 2 if the abducted Sim is an adult male, he will come back pregnant 100% of the time so long as there are less than 8 household members when he is abducted, and in three days he will give birth to a half-alien baby whose other parent is the unseen NPC Pollination Technician. To be abducted (or have a relative abducted) is a want for Knowledge Sims, and a fear for others. The odds of being abducted are very low, on the order of 0.05% percent for each animation cycle.
If the Nightlife Expansion Pack is installed, a Sim who has been abducted at least once can be abducted while using the ElectroDance Sphere on medium or high, even if he or she was a teen when abducted the first time. Each Dance Sphere will only trigger one abduction, but the odds of abduction are much higher than with the telescope. [confirmation needed]
In FreeTime, all of the telescope actions have a chance of alien abduction, but the Aspiration Reward for Knowledge, Summon Aliens, has your Sim create a spotlight with a flashlight and telescope, with a huge chance of abduction.
Aliens are very important to the Strangetown story (especially with The Curious Brothers), and play a lesser part in Pleasantview except in the case of Bella Goth and the Caliente Family.
If you want a Sim to be abducted, use the "boolprop" cheat, then shift-click any telescope, and then select be abducted. This cheat dosen't work after Seasons or Bon Voyage is installed. It also will not result in the Sim having the memory of alien abduction, but will still result in pregnancy for male adult Sims more than 6 days from Old Age.