The solo parent Marisa is busy in the process of constructing an enlargement the den. While this is going on, she is oblivious to the fact that every one of her babies have been killed or about to die.
The reason is; Marisa was too heavily preoccupied with expanding the nest and she didn't hear the cries of her children over the intoxicating sound of her own very easy workman's song... the baby Alice's have gotten over excited and raped the Baby Marisa's to death, and being far too young for that sort of thing, they overexerted themselves and are now so worn out that they too are dying.
Born easily, they also die easily. Carefree Marisa's inattentiveness has resulted in a charming tragedy.