Whoever comes up with mouse birth control bait is going to be the next billionaire. My sister lives in a Mcmansion in the upscale suburbs and she has been fighting mice since a few weeks after they moved in not long after the house was built.
Two years ago we moved from suburbia out to the sticks into a 125 year old (restored) farmhouse on 20 acres with four barns and one detached all metal two car garage and workshop, and I was horrified at the number of mice I was seeing and hearing out in the garage. When I found them nesting in the fuselage of one of my scratch built radio control planes out in the workshop, I declared all out war. I nailed at least 20 of them just in just a few days using nothing more than snap traps and peanut butter. I put out eight traps in one night and all eight of them had a guest the next day. I only have two traps out now, for the first time in over a couple months and its been a few days since I got even just one so I think I finally made a sizeable dent in the local population, but its going to be a never ending war I have a feeling.
I would caution against using poison baits. Anything that eats the carcass of that dead poisoned mouse will also get poisoned. You dont want to go killing off the snakes, vultures, owls, hawks, and anything else that feeds on them. A bag of four snap traps from Home Depot is well within the budget of even a homeless person and if you are as much as a cheapskate as I am, they are plenty reusable too. I have a few that have dried blood and fur on them from previous victories and are on their fifth or sixth go around before they become so gross even cheapskate me says its time, and I replace them.
I've moved away from storing anything out there in bags or boxes where they can nest, and have a whole arsenal of clear plastic bins with snap on lids to store anything and everything, $6 a piece at Walmart or wherever for a decent sized bin and everything in them stays mouse free, clean, dust free and no spiders or centipedes or other creepy crawlers as well. In the garage and workshop all the gaps between the metal and concrete by the floor are sealed up now with wire mesh and spray foam, and do whatever I can to minimize any gaps in garage doors or entrance door seals too. This cut down the interior spider and wasp population as a side benefit, because that was an issue too. I hate spiders and wasps as much as I hate mice.
Just a bunch of little battles to make it as difficult as possible for them to exist where you are is all you can do. You'll never deter them enough to make them nonexistent, they are very smart little beasts and have all the time in the world to figure out whatever we spent hours or days we build trying to deter them and they will always win, but you can make it as difficult as possible and severely cut down their success if you dont mind the minor though never-ending fight.
Lots of clever contraptions and ideas on Youtube, if you want to make a hobby out of it....