Another danger of using D-Con or any poison is that the mice might crawl into a wall and die. You will know it when the smell of dead mouse permeates your 2X4's and drywall.
Traps are tricky to set, at least the low quality traps on the market today.
However, there is a quick and (not too) dirty way to catch a whole herd of mice if necessary:
Get a 5 gallon plastic bucket and fill it half way with water. Smear peanut butter all around the inside rim. Take a plank of wood, maybe 6 inches wide and 3 feet long, and place one end overlapping the rim of the pail and the other end resting on the floor. The mice will scamper up the plank to get the peanut butter. Once at the top, they will try to maneuver into eating position, but will fall into the pail and drown.
It works. I had a trailer at a campground for a few years and mice were a problem. I would come up on weekends and usually had a half dozen mice in the bucket.
If you build it, they will come.
