This is the time of year for them to find their way in.
I don't think you have a big problem and if you did I think you would know. Just keep after them and keep the house sealed up to keep them out. They are looking for food, water, warmth and a way to get in.
Traps set with peanut butter I have found work the best. The good old wooden base spring loaded traps work best.
Good luck, I was told yesterday it was that time of year and to set a few traps in the basement.
Oh and if they are around you will see their droppings.