They believe they were put here to pro-create and boy do they! This trait is available through CAS with the other 'lifestyle' categorized traits. Even if your Sim isn't married they will still want to make children with whatever sim is around. It seems as though the 'Family-Oriented' cheat fulfills this is some way but my trait takes it to the next level! Not only will your Sims have the need to make more children, they will not want to stop. Locking in a good future generation is very important to keep the game going longer.

I often find the Sims lacking in the natural drive to procreate. :lovestruc Baby Maker Trait :lovestruc This trait now works after the Pets patch.