mother mouse eating babies

Question
I GOT 3 FEEDER MICE FROM THE PET SHOP TO FEED TO MY SNAKE.  ONE OF THEM WAS PREGNANT SO I DIDN'T FEED HER TO THE SNAKE AND I PUT HER IN A CAGE I HAD HAD MY LAST HAMSTER IN, PUT IN NEW BEDDING, PROVIDED HER WITH FRESH FRUITS AND NUT AS WELL AS HAMSTER FOOD WITH NO CORN.  TWO DAYS LATER (LAST TUESDAY) SHE HAD 11 BABIES DURING THE MIDDLE OF THE DAY.  SHE STAYS IN MY ROOM 24/7 AND I KEEP A BLANKET OVER HER CAGE AND THE LIGHT AND TV OFF WHEN I'M NOT HOME.  IT HAS BEEN A WEEK AND SLOWLY THE BABIES ARE DISAPPEARING.  I'M SURE SHES EATEN THEM BECAUSE I KNOW THEY HAVEN'T GOTTEN OUT.  I'M DOWN TO 7 NOW.  I'M NOT SURE WHY SHE IS EATING THEM THOUGH.  SHE DOESN'T MIND ME HOLDING HER, ALTHOUGH ONCE IN A WHILE SHE DOES NIP AT ME.  SHE LETS ME REACH INTO THE NEST AND MESS WITH THE BABIES AND TAKE THEM OUT AND SHE DOESN'T CARE.  ITS NOT AFTER I HOLD THEM THAT SHE EATS THEM, ITS WHEN I'M NOT THERE.  I CAN HOLD THEM ONE DAY AND THE NEXT MORNING THEY ARE STILL THERE, AND THEN WHEN I COME HOME FROM SCHOOL ONE IS GONE.  I STARTED TAKING HER OUT ABOUT 15 MINS A DAY TO EXERCISE AND GET A LITTLE BREAK FROM THEM WHILE I PUT HER IN A BALL TO RUN AROUND THE HOUSE.  I'M NOT SURE WHY SHE IS EATING THE BABIES THOUGH. AND SHE IS ONLY EATING THEM ONE AT A TIME.  WHY COULD THIS BE?  AS I SAID, ITS NOT BECAUSE I'M MESSING WITH HER OR THEM, BECAUSE ITS WHEN I DON'T.  SHE HAS PLENTY OF ROOM IN THE CAGE TO GET AWAY FROM THEM FOR A LITTLE WHILE AND IT JUST DOESN'T MAKE SENSE TO ME.  I WATCH HER FEED THEM EVERY TIME I PUT THEM BACK IN.  SHE IS GENTLE AND FRIENDLY TOO.  COULD YOU HELP?
THANK YOU,
BREANNA MELVIN

Answer
Dear Breanna,

There are a couple of possibilities. If the babies die normally, the mother will eat them.  If they are sick or defective, or she thinks they are, she will kill them and eat them.  Or if she is confused and upset or thinks they are in danger she may kill them and eat them.  Some mice, very, very rarely, just aren't good mothers.  Feeder mice are often not bred for any other characteristic than to survive until they are old enough to be eaten.  They may have any number of genetic or personality defects.  Of course this mouse should not be bred again.  But that doesn't mean she won't be a good pet.  

best of luck,

squeaks

Natasha