Theory:

     He ran towards his parents gaily and walked abreast of them for a while, being, however, soon left behind, attracted by the little insects and worms along the footpath that were teeming out from their hiding places to enjoy the sunshine.
 
     “Come, child, come!” his parents called from the shade of a grove where they had seated themselves on the edge of a well. He ran towards them.
Explanation:
 
The child ran towards his parents to keep pace with them. He walked next to them, but after a few steps, he stopped to see the insects coming out of the soil to enjoy the sunshine. Once again, the child was left behind.
 
His parents called him. They sat on the edge of a well under the shady trees. The child ran and joined his parents.
 
Meanings of difficult words:
 
Numbers
Word
Meanings
1.
AbreastSide by side and facing the same way.
2.
Teeming outTo pour or empty.
3.
Grove A small wood or group of trees.
Reference:
National Council of Educational Research and Training (2006). Moments. The lost child - Mulk Raj Anand (pp. 01-06). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.