"Those were children," Vanitas states, clearly not comprehending what the issue is here. "They'd get scared of anything that scurries around in the darkness of their own room."

That's not the case here though. It isn't night time. His Unversed really are doing more recon rather than looking to attack. At least they won't unless they are attacked first but Vanitas has a harder time controlling them the farther away they go.