Until quite recently, the idea of a humane mouse trap would have been treated as a joke, but no more. Here are two simple ideas for catching mice without harming them.
1. Deep Glass Jar
Simply take any glass jar that is more than 8 inches deep, bait it with your favorite mouse bait (chocolate is excellent but don't leave chocolate out if you have petes), and then position it against something that is 4 to 6 inches high that a mouse can climb onto.
The smell of the chocolate is irresistible to the mouse. It climbs up to reach the top of the jar, leans over to try to reach the chocolate, and falls in. The mouse cannot climb out of the jar, is not harmed, and can be safely released.
2. 2-Liter Pop Bottle or Similar
It helps if the neck of the bottle is fairly broad. All you need to do is use a very sharp craft knife and cut the top off the bottle just below the shoulder. Invert the top and place it inside the remains of the bottle. If it tends to fall into the bottle, find a way of securing it without making it a permanent join. Spring-loaded clothespins are ideal. Glue the bottom of the bottle to a base about a foot square and put an inch or two of sand or gravel into the bottle. Set the bottle trap next to something high enough for a mouse to climb up, add bait, and secure the upside down top.
The smell of the bait will attract the mouse and when it leans over the bottle, it will fall into what is now a funnel and go through the hole to follow the smell of the bait – ready to be released when you find it.