Oh you ignorant people in the USA. In the Australian wheat belt, the mice population is cyclic. Our droughts kill off the plague numbers of mice because there is not enough food for them to survive, in very large numbers during drought periods. Then in the progressive good seasons, their numbers grow rapidly until they are in plague proportions, and considering how quickly the number of mice grows, the population of mice can double every month or so.
The snakes are a farmers best friend because their numbers also follows the mice plague numbers as well. When the number of mice is high, so to are the number of snakes. When the mice numbers are low, the number of snakes is also low. That is the nature of the life cycle of mice and snakes.
Were I live, we occasionally see baby snakes in the house, but out in the yard there are few to be seen.
In the USA, you have snow that controls the number of mice from one year to the next. However, I would like to point out that most people have a mice or a rat living within five meters of them all of the the time.
So you city folk, do not fret, you have a mice or rat problem living with you all of the time.
Shalom