Do cockroaches is eating cardboard in my attic?

Yes, cockroaches can eat cardboard, as it is made of cellulose, which they can digest with the help of bacteria in their guts. They are attracted to cardboard because it can provide both food and shelter. If you find cockroaches in your attic, it's important to address the infestation, as they can also pose health risks. Consider sealing any entry points and using traps or professional pest control to manage the situation.