In a large saucepan, over medium high heat, add the corn syrup and sugar. Stir constantly while you bring it to a boil.
Remove the pot from the heat and add the peanut butter and vanilla. Stir until smooth.
Mix in the cereal.
Stir until well coated.
Use a silicone mat or wax paper.
Drop the mix, a spoonful at a time, onto the mat. Roll the drops into balls and cool.