Theory:

Mother Wolf: (In a soft tone) How little! How naked, and – how bold!

Narrator: The baby was pushing his way between the cubs to get close to the warm hide.

Mother Wolf: So this is a man’s cub. Now, was there a wolf that could boast of a Man’s cub among her children?

Father Wolf: I have heard now and again of such a thing, but never in our Pack or in my time. But see, he looks up and is not afraid.

Narrator: The moonlight was blocked out of the mouth of the cave, for Shere Khan’s great square head and shoulders were thrust into the entrance. Tabaqui behind him, was squeaking.
Explanation:
 
Mother Wolf looked at the baby and was surprised to see how little and naked the baby looked. The mother spoke in a tone that was so soft and warm. She said, 'how little, how naked, and how bold!'
 
wolf-1336229_1920.jpg
Mother Wolf gives the child a warm and motherly look

Meanwhile, the baby was moving among the cubs. The night neared, and it was getting colder. Moreover, as the boy wasn't wearing any clothes, he pushed through the cubs to reach the warmer place among the cubs.
  
Collage (1).jpg
The baby with the wolf-cubs

The child blissfully smiled at the wolves while they discussed how bold the child was. It could be seen that Mother Wolf was considering the prospect of having a human child as her own, for she asked her husband whether there was a wolf that had a Man’s cub among her children. Though Father Wolf had heard about such a thing, he had never witnessed the said scenario in his entire life.

The line, "have heard now and again of such a thing, but never in our Pack or in my time", spoken by Father Wolf, can mean either of the following:

1. The stories that the father had heard could be mere rumours.
 
\(or\)
 
2. The boy wasn't the first to live among the wolves.

Back to the play, we see that the cave had suddenly become darker as something had blocked the moonlight from the cave entrance. Looking up, the wolves discovered the great head and shoulders of Shere Khan pushing through. Tabaqui was seen at the back of the tiger.
 
shutterstock_1156421167.jpg
A cave entrance through which the moon is visible
 
Meanings of difficult words:
 
S.No
Words
Meanings
1
Warm hideThe skin of a large animal
2
Boast To talk about something in a proud manner
3
Mouth of the caveCave entrance
4
ThrustTo push suddenly and strongly
5
SqueakingTo make a short, very high cry or sound
Reference:
State Council of Educational Research and Training (2019). Term-3 English Standard-6. The Jungle Book. (pp 116 - 121). Published by the Tamil Nadu Textbook and Educational Services Corporation.