Critters sometimes fail to notice the player?

[Question2]

This seems to happen most often with certain encounters, like random radscorpion encounters.

You can kill a few radscorpions, but the rest will just ignore you and keep walking around. Your companions wont target the remainig scorpions either.

Anyone else noticed stuff like this?

 

[Question2]

Okay, I think this is because the critters have PE 3 and at night, they are pretty much blind and cant notice the player at all until you hit them.