I did not design this model, but printed it from Thingiverse and found it so efficient that I thought it should also be available on Printables.

What is nice about it, is that you only need a rubber band and about 25 cm of string, which anybody probably has at home (no bottles, jars or such things needed).

Place some bait at the end of the hole (butter biscuits worked well for me), and then, place string around the main part to block the entrance of the hole (make two small knots at each  end of the string). The mouse has to chew through the string to get the bait, which will then release the arm and kill it. Replace the string after use, and that's it!

Everything can be printed without supports.

The bolt is not threaded, you have to glue it to the plate part.

This trap will kill the rodent, so be aware of that.