Q.subterranean critter control
How do I control the voles and moles that get into my tunnel garden? There is no wire lining.
Sheila, There are several options besides barriers, poisoning or tapping are most commonly used.
Here are some articles with background and products:
The following guide from DoMyOwn.com has four sections, review them all to get some good overview of identification and possibilities for control. Don't overlook the 'prevent' section that discusses repellents with some examples of products.
https://www.domyown.com/vole-identification-guide-a-617.html
https://stoppestinfo.com/226-how-to-get-rid-of-voles.html
http://www.havahart.com/articles/vole-trapping-tips