River wouldn't have understood this 'hive' feeling because she did not feel it. These other zombies were not like her, and even on a basic level, she knew that or could feel it. They might want what she wanted, but they would not go about getting it the same way.
River would have smiled, if she were alive. And there probably would have been a kiss, just because she had not seen Hannibal in a while. But she stared at him, eyes dark, spark of life no longer there...
Whatever had been done to River's brain didn't stop, just because she was no longer alive, in the strictest sense. She felt, on a limited basis. She knew, on a limited basis. And she stepped back, grabbing the hand she knew had six fingers and holding onto it.
The step back was a good deal less graceful than her average movements.