a pile of dead and dying bees outside the hive

This is my first hive, so bear with me..
My new brood is hatching and the workers have dragged a hundred or so bees outside and killed them.
Most of them are not drones, but seem to be young workers. They're not flying. But their bodies and wings are normal. I can't see any sign of disease.
Is this normal? I thought they only got rid of the drones. The hive and hive equiptment are brand new and otherwise they seem to be doing just fine.
Thanks for any help...
Cyril

If you see no mites attached to their bodies, especially between the tergits on the abdomen where they burrow in and can hide, I would have them checked for trachael mites as a thought.
Bees don't throw out newly emerged bees without good reason and it is the end of July now.
Sincerely,
Dee