I realized that the tong case is not only the cheapest option but also the most effective.
After a short time I had already caught 8 voles. However, one already has to deal with some of the habits of the mice. Otherwise, you quite often catches earth because the voles which opened courses zuwühlen without going quickly into the trap. Best fishing successes I had with the following procedure:
Make 1st gear locate
Open 2nd gear
3. In about 30 cm distance from the opening to open the passage again and there place the trap. The whole thing make in both passage directions.
4. The traps then good cover (air- and light-tight!)
The mice then come to the main opening to close again because they can not tolerate drafts and must forcibly through the traps to go to get to the hole. I tried supercat with the swissino. But unfortunately did not work out.
The Sugan vole from Neudorff I had unfortunately once success. Most of the cases were only zugewühlt. You can put these unlike the tong case even in a passage direction.