If you sit down and work out the time and costs associated with trapping a single mole at x location, it becomes quite sobering.
I would encourage you to do that, write it all down and then work out the hourly rate for a given tariff of charges to see if you're actually making money.
My advice would be to advertise locally and do local (I am emphasising local) work at a fair price, and grow your business by offering a great service close to home. That way you won't be spending hours sat in traffic. If you do need to cover a larger catchment area however, you need to be mercilessly realistic about your charges for outlying clients. Time and fuel need to be well covered or you'll be on less than minimum wage before you know it.
That said, if you've got a reliable set of knees, it ain't a bad life