Mary Jane's Cat Supplies

I have a male cat (neutered) that gets into everything. He opens cupboards, closets and knocks things off of the counter on purpose. He even steals his treats out of the cupboard. He has a system, he knocks the treats out and my other cat mauls the bag, then he eats the treats. I ran out of treats, so now when I am not at home he steals other bags that look like the same size as the treats, like a bag of gravy and chews them open.
I got an automated spray can called ssscat, but he figured out that he can just knock it over, or he plays with it.
I was thinking of using mouse traps, but since he figured out the ssscat, I'm sure once the mouse traps are set off he'll realize he can get into the cupboards again.
I live in an apartment so drilling holes in my cupboards for child-proof locks is not an option.