We had heaps here, at one point we were catching up to 10 a day and our local woolies had sold out of all mice related products
On our traps we use peanut butter and sometimes we sprinkle a little parmesan.
Someone mentioned plugging little holes with steel wool, they don't like chewing through it, you can also use silicon on smaller holes but they may bite through that over time.
We had them for WEEKS but we haven't caught any in a while now, even though we know they are still around somewhere.

The other thing that helped was we re-did all our pantry, everything loose went into containers so they couldn't get into anything and thus took the temptation away