My 6 month old DD started this thing over the weekend where she shakes her head from side to side. It seems to mostly happen when she's tired. I have no idea if this is just a new discovery she's made, but it makes me kind of nervous. We have her 6 month WBV tomorrow so I'll definitely ask her ped about it. I just wanted to know if anyone else has experienced anything like this. Oh, and I know it can be sign of an ear infection, but she doesn't seem to have any other symptoms so I don't think that's it.