My boys do that too... haha they are on NutroMax lamb & rice dry kibble. They are 1.5 years old.
Just when I think they are settling down for the night, they jump off the couch and go ballistic! Running like mad men, playing rough with each other... its hilarious! But I think its normal! Sometimes its just 1 word or a look I can give them that sets them off into nuts-ness like that.
Oh yeah, my mom has a 4 year old Shih Tzu who does the same thing! She's on Nutromax also!