[SutterBrother]

The most important part is the house seal up. You don't want them getting in. A pest control expert will often have experience and see things you might not. Mine saw "runs" where the grease from the fur was left on surfaces (70 year old house, moved in after elderly couple moved out).

Make sure you're not doing the dumb sh-t stuff like leaving pet food or garbage around your property. If you feed em...they will come. If you have a veggie garden, or fruit trees, and aren't keeping up with them, it's going to attract vermin.

Once that's done, exterior traps with poison bait. One on each facing side (usually 4). They carry the bait back to the nest and it kills the crew.

Interior traps baited with peanut butter. Run those trap lines twice a day. Replace the traps if you get a hit. You'll see smaller and fewer mice with time.

If you start to smell sickly sweet scent, it's probably decomposition. Find it (even if you cut drywall to do it) and remove it.

Finally - don't get a cat unless you want a pet cat for ~15-20 years. Like... duh.

(I got my cat from someone who thought she would be a mouser instead of... a sleeper? I don't have mice (anymore) but have seen her casually watch a cricket walk in front of her face and she does f-all about it).