Well, I called NPR's comment line and tried out a new version of my comment.
You are allowed up to 60 seconds---this called for some heavy editing!  I hope
you'll indulge me in sharing this work with you all.  It was pretty stressful
making this call, and I feel I need to touch base with my LactNut buddies.

BEGIN
Your story about the unexpected high infant mortality among the rats on the
space shuttle told how rat babies died when their mothers didn't nurse them.
I don't know why this should surprise anybody.  Reproduction is risky for all
of us mammals---especially under stress.  Picture a mother who struggles to
keep her pups attached…but they keep floating away.

What bothered me was hearing the cause of death identified as---quote---bad
mothers.  Don't blame the mothers!  Baby feeding is set of a survival
techniques that have evolved to suit each mammal's normal environment, so that
whales nurse under water, bats can nurse in mid-air, humans nurse anywhere,
and rats expect to nurse safe in their nests.   The wonder of the shuttle
story is that, despite weightlessness and lack of foresight by the humans who
thought up the experiment, some of the mothers actually did figure out how to
keep their babies alive, using instincts they brought from a world where
gravity is the law.