Signing???

Aaron started signing milk tonight!  The first time he did it I wasn't hardly paying attention b/c my 3 yr old wasn't listening and I was trying to discipline him and then Aaron in my lap starts crying and I look down at him and he is holding his arm up to me and his sweet chubby hand is making the sign for milk over and over again!  I couldn't hardly believe it, but he did it again later. He had been sitting with dad while I got big brother to bed and when I came back he was fussing a bit so I picked him up and started playing with him on my lap.  Then I asked if he wanted some "nahnies" and made the sign for milk and he looked right at my hand and then laughed and looked up at me and raised his hand and made the sign back to me!  I don't think he quite gets what it means yet because when I put him to breast he really wasn't interested, but I do think he likes that he figured out how to do it.  Maybe he thinks it means "mommy" or something.  Anyway, I'm still in shock.  Not even 6 months and he is starting to sign back at me!