Along with all the other chemicals we don't use, we don't use Ivermectin wormers for our sheep. Ivermectin persists in the dung and kills earthworms (and compost worms if you stack the manure) so farms where dung from animals wormed with the Ivermectins is spread on the pastures have few earthworms. Our smallholding is surrounded by larger farms where they use Ivermectin wormers. When we had our mole plague it was strikingly obvious just by looking to see that the moles all lived in our fields and not the neighbours. One neighbour tried to say that moles were spreading out from our place but had to admit that the traffic was in the other direction
As moles make their tunnels and patrol them in order to capture earthworms to eat, their presence on our holding but not the surrounding land demonstrates that we have plenty of earthworms (a sign of a healthy soil) whereas they don't. This is confirmed by digging.
Many years ago when we first moved here, we bought a couple of loads of muck from a neighbour's byres, to use in the vegetable graden until our stock had produced its own. At first I didn't understand why it simply didn't rot down as it should, but was still remarkably unchanged after a couple of years. Eventually I found out that they use Ivermectins and its effect on the resident earthworm and compost worm populations.
So it's not the pesticides and herbicides which affect the moles, but which wormer is used in the animals providing the fertility.