Here is some information about different types of pest we see most!
Cockroaches are most common insects found in homes, especially in and around kitchen areas. They can't see you. Roaches try to avoid air currents: if they sense the wind on their back, they will flee. They will also avoid light, and seek protected nooks. If the closest nook happens to be the shade under your sneakers, they will try to crawl under there because they can't understand that your shoe is a part of you, the big thing that turned on the light and made air currents and vibrations and scary things. It doesn't help that roaches can't always see above them: their heads are protected by their pronotal "shield," so they can see a bit in front of them but little or nothing above them or behind them the way flies do.
They will eat almost anything organic, and a decent amount of non-organic waste. Now, they prefer dark greens, citrus fruit, some species a bit of meat… but overall they aren’t picky. If you are asking for a colony of “pets”, when I would recommend saving salad that’s going bad, apple cores/cuttings, old citrus and potatoes, etc. If you’re asking “what are they eating in my house so I can eliminate it and get rid of them”, then the answer could literally be almost anything. They need a ready source of moisture more urgently than they need food, so eliminate areas of excess moisture first… once you’ve addressed that, look for anything that’s organic… a trash can that leaked or has accumulated a stash of crumbs, open/available cracker boxes or flour, etc etc.