Seems like it is either feast or famine when it comes to trapping moles. I have a large city lot, and the moles have gotten out of control. Ridges everywhere. I’m a big believer in trapping them, and have had very good success in the past. But this last year I had rather poor results, and the front yard is more ridges than flat! When it is dry, runs tend to run deeper in the ground, and in sandy soil, moles usually push right through the trap without tripping it. The recent rains increases resistance in the soil, and they are more likely to push upwards than forwards, thus releasing trap.
My best success is when trapping on a long straight run with is significantly pushed up. I got 2 moles in 3 days trapping in the same spot using a Victor Out-O-Site trap. Moles are territorial, but they do use common runs.