They were already coming in. The new ones probably would have found their way in with or without the bait seeing how they are trying to nest down protected for the winter.
regular baking chocolate chips or a small piece of candy bar stuck into a dab of peanut butter is the best bait for mice. snap traps only. "humane" catch and release is just feel-good fool yourself BS. there are repeater traps but they are kind of gross and either the early caught ones die and stink, or you have to deal with the live later caught ones, but they are ok for barns or sheds that don't get much human traffic (a little cruel but not as bad as glue traps)
best are snap traps, though. mice aren't as smart as rats but for either if you have a stubborn one, feed it on unset traps for a few days and then set the trap. don't clean used traps, the dirtier the better if you can stand to handle them. keep them set year round and just try to make a habit of checking them occasionally, especially in warm weather so you don't get a fly problem. around here they want to come in in the fall, other places may have different "invasion" periods. don't worry about drawing more in with set traps, they will come in anyway. best is to figure out where and block but I know how difficult that can be in some situations. I have a LOT of personal experience in this area.
snakes and cats are your friends but they won't catch them all. if you see one, there are at least 10 more you haven't seen.
now can somebody help me with rock squirrels? just had one fall out of a wall opening (we took out an ancient heater and haven't done the planned remodel of the opening) and run to the back room, causing lots of obsessed dog action before it finally found its way out to the porch and out that door. they are undermining my chicken coop and stealing pecans. I don't have time to sit around with a bb gun or .22 and pick them off but I sure am sick of them.