It's supposed to be intarsia.

Intarsia is one of those knitting techniques that I had no desire to ever attempt. I was never ever ever going to knit my kids sweaters with big blocky animals on the fronts. Then I checked out Creature Comforts from the library and saw the cute little chicken sweater and now I've got to make one...

So I'm attempting Mousie Mousie from Handknits for Kids and it seems to be working. I don't really like this technique, but if it gets my baby a cute sweater with a chicken on it, I'll figure it out.