Agree with FW. The other thing I've been told is that at this time of year they're making tunnels looking for mates - so it's not just about earthworms. I don't know if that's true or not.
BH traps them here, as do the farms round about. He's told me that it is a sure death but not a very quick one. So he rues the day they banned strichnine, which he reckons was quicker and surer. And he wouldn't have used it if he thought it was harming other wildlife. However, it's not an option now.
We've had people trap them for us too - the going rate now seems to be £5/mole. Make sure you get the bodies - there have been stories of several farmers paying for the same moles
and even some farmers paying repeatedly for the same moles! (Cue my story about 'recycling' my milk teeth and the Tooth Fairy not twigging on...
)
BH and I were talking about the moles the other day, and saying that if we eradicated them we'd probably have to pay someone to do some soil aeration... so they're a mixed blessing in a way. But the biggest issues relate to the listeriosis risk - as FW says, lambs seem to love to lie on them and we are sure cause more problems with mucky eyes and inturned eyelids, some ewes even lamb onto them, and also, any humps of soil left as the grass begins to grow for cropping can end up in the silage or even the hay - and then you really do have a risk of listeriosis.