How do you stop a parakeet from having baby?

You cannot prevent a parakeet from having babies. However, you can prevent them from breeding by:

Separate males from females. Placing the birds in separate cages, or in different areas of the same room.

Remove nesting boxes. Taking away any boxes or other materials that the birds might use to build a nest.

Discourage breeding behavior. Removing any objects or materials that may trigger breeding, such as nesting material, sticks, or toys.

Control the light cycle. Providing only 10-12 hours of light per day can deter breeding behavior.

Provide a balanced diet. Feeding a healthy diet that is low in protein and high in fruits and vegetables can help to suppress breeding behavior.

Distract the birds. By providing plenty of toys and other things to do, you can help to distract the birds from breeding behavior.