And one stands alone

Last week purchased a dozen 2 week old mixed wyandotte bantams from a man who ordered too many from a hatchery. (For $3 a piece, I'm kicking myself for not getting more...especially since my brother had asked to split them with me once they're ready to go outside.) One of my nieces was holding one when she wasn't supposed to be (no adults in the room), it jumped out of her hand and hurt it's leg. Yesterday I found it trampled. Today I noticed one of the chicks was sort of staying away from the others. I haven't noticed any weird behavior, but was wondering why this one isn't with the others. This is my first time with baby chicks, so maybe I'm just being paranoid after yesterday's trampling.