Although he of course could not know for sure about the 'whys' and the 'hows', he could tell that the Big Daddy was - in a way - nervous. An odd thought considering that Bo himself was not exactly of threatening appearance.
He didnโt understand a lot of the babble the Splicers went on with, but he could detect the threats. Although Boโs tone had been friendly and warm, Iota was immediately set on guard as he observed him, his posture rigid and ready to defend himself.