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My first thought is you are seeing the onset of seizure activity. Sometimes it is impossible to know what triggers this. Usually it will progress over time to full blown seizures.
To be on the safe side, you may want to consider having bloodwork run in the near future to rule out other causes.
With seizures they can have signs like what you are seeing and then go into the flopping on the floor.
I would get him checked out since he has had 2 this month.