When a customer calls me about moles I let them know that I'll sub the work out and just add it to the bill. I do give them a heads-up that the rate around here is now $70/mole.
That's one thing that irritates me. 5 years ago it was $25, then $50, now $70. For putting in mole traps!
On my own lawn, when I see a fresh run I put the end of the water hose in the top of the run and turn it on. And stand WITHOUT MOVING, with a shovel, further down the run. It takes several minutes, but he will surface, and then WHAM!
Here's the deal...take care of moles ASAP because they destroy lawns very quickly.