Alien Abductions

In the past it was rare that my sims were abducted by aliens.  Now it seems like in all  my games sims are being taken, even if they don't have a telescope.  I have one male sim who got pregnant twice even though his settings say that he couldn't get pregnant.  Is there a way to stop the kidnappings that anyone knows of.  It used to happen only to my sims who use the telescope a lot.