Social worker

The Social Worker is an NPC who will take away a Baby, Toddler, or Child if their needs drop too low. They may also be taken away if a player has the Expansion Pack Seasons, if the temperature drops to low on a Sim, they will also be taken away. If there are any other children under Teen in the house, they will all be removed with each other. Once they are taken away, they will all be available for adoption by a different family (or families). Once a person has the memory of having a child taken away by the Social Worker, they are ineligible for adopting ever again.

There is no possible way to stop the Social Worker from removing a child without cheats. Even if there is a wall around the children the Social Worker will teleport the child out of the structure and to her car.