Not from the photo but the description fits voles. Moles will certainly make hills in one line, where the entrance is vertical. Voles can make dispersed pattern hills with angled entrance holes. Although for some reason for us they don't hill when working in garden beds, only in sod areas (orchards). Depending on the year they can be a big plague eating veg other years just a nuisance pushing up seedlings or direct seeded plants. The latter seem not to care as long as watered in constantly. I did have times when i had to keep grounding in a planting of lettuce various times, real PIA. Home remedies include stick in ground with disposable metal baking sheets tied to them (noise, vibration), solar powered vibration gadgets, ricin extract to ward them off (very posionous), planting euohorbia lathyris plant (posinous)... None of which i believe is effective if you have serious problems . Gassing the colony with exhaust from car or tractor into to tunnels is apparently brutally effective, just leave one tunnel entrance open for the exhaust tube, close the rest. In the US i understand there is authorised organic vitamin D3 based bait+posion against rodents. Cats, predatory bird perches... or certain dog breeds are good if you can live with the digging. We tend to use special vole/mole snap traps in problem areas. These need no baiting just careful setting up in the tunnels. Other folk use regular mouse trap, baited inside pvc tube on the surface. Especially in high vegetation areas and along greenhouse wallswhere the voles tend to travel on the surface. a few kills and usually they get the message. Again it all depends on the yearly population fluxes.
Thanks for the thorough answer. The snap trap in a tube sounds promising. I am also trying to keep shelter areas to the minimum. They love living under tarps!
Yes they do... to an extent that they actually kind of till the soil under the tarped areas... difficult to go notill with so many of them around hehe. But I kind of like the result many times it makes for a very loose top finish to work with... silver lining.