Rat swaying

Question
We purchased two rats for our four year old daughter. One is very active and rambunctious. The other is active but when she stops moving she will start swaying left and right and will continue to do it until she moves again. Its just her head that moves.It kind of reminds me of autism, is that possible? is it normal for rats to do that or could something be wrong with her. She is a tan and white fancy rat between 4-6 months old. They both have healthy appetites and play all night. I'm just little concerned with her swaying it just doesn't seem normal.

Answer
does she have ruby eyes.. if so this is normal.. rats with pink and ruby colored eyes have a harder time seeing so they sway back and forth to be able to see better, its kinda like people who lose their glasses. they will squint and move their heads all funky too

its normal and nothing to worry about..