i'm not saying the rats learned it from you at all. i'm saying that if these rats came to you from an unknown 1st origin such as from a pet store or as a rescue, you can't be sure of their past experience and perhaps have learned to fear small children through previous rough handling. as far as rats being aggressive to people they don't know seems odd. normally rats are very friendly, socail little critters that like just about anyone who's nice to them. and if you believe you know the reason for their aggression why are you asking us?