I don't know what ate the leaves but the damage in the pictures looks rather minor. If that is the worst of it, I would skip the pesticides and live with a few holey leaves.

FataMorgana

grasshoppers?

@biscgolf - I am not sure but I dont see any around. I think grasshoppers might be big enough to be spotted. I just cant find any insects.

Has anyone tried diatomaceous earth for mint?

Grasshoppers hatch from very small eggs as tiny nymphs. They can be easy to miss if you're looking for larger insects. They can hop very well when young, but don't develop their wings until mature. Be observant for all kinds of critters in the garden, big AND tiny.

I just wanted to update everyone that I found a solution to who is eating my mint. I dont know what the pest was, but spraying with Spinosad helped me get rid of whatever it was.