This seems quite similar to human behavior, except that instead of infanticide and cannibalism, we use abortion.
I realize that it counters any idea that rats find their offspring precious. But this does raise the question rat just asked you. If we can see that mothers can have issues post birth, why shouldn't infanticide be allowed. Heheheh... or cannibalism?
holmes
"Some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new dark age." (Lovecraft)