There are many reasons why the mother monkey only cares about herself and doesn't give it to the little monkey, including:

1. Protect the little monkey: The mother monkey may think that some foods are harmful to the little monkey or not suitable for them to eat, so she only eats them herself to provide safer food for the little monkey.

2. Educate the little monkey: The mother monkey may want the little monkey to learn to find and get food by herself in order to survive independently.

3, control the little monkey's food intake: the mother monkey may want the little monkey to control the food intake and avoid eating too much.