Awww they are too cute (and Momma Cat is a lovely girl too)! Sorry about the littlest one that didn't make it but generally animals do seem to sense when an offspring isn't born right and push them away like that. It's like somehow they know that their resources are going to be wasted trying to raise the sickly one so they push it away to let nature take it's course. Harsh but it does allow for her milk to go only to the healthy babies that can use it.