A couple of things came to mind when I read these posts.
1. Puppies under a year go through a couple of 'fear' stages where they suddenly become fearful of familiar things or people. I believe one stage is around 4 months and the other at about 10.
2. This behavior could also be a form of seizure from a health related issue, food allergies or other things. If you would like to explore that a little more you can read around this website:
Canine epilepsy and diseases that cause seizures in dogs
It is full of information and has descriptions of different types of seizures. Hopefully it isn't seizures in either of these puppies.