Exterminating mice in the garage?

So for a while we've had mice in the garage and now we are trying to get rid of them, just today we put out poison and sprayed down some food that they got into. It's been about half an hour since we've done so, how long should I expect before I start seeing less of them (predicted about 4+ of them)? And if none of these things work what else could I try?Exterminating mice in the garage?
Your first step would be to block the way their getting in. The poison your using is probably slow acting if its over the counter. It will work, but you have to block the entrances and give the poison time to work.Exterminating mice in the garage?
I found this method by accident. I leaned a rake against an almost empty 5 gallon bucket that contained bird seed. A few seeds around the bucket must have attracted mice who eventually ran up the rake and fell into the bucket.





You can release them outside, or not.