It's probably only one mole - apparently they are solitary creatures & only get together to mate. Maybe it's that time of year though..........
However, there are a few things you can do to try to make them go elsewhere. They don't like noise or (to them) strange smells, so you can try the following:
pour a small amount of strong-smelling stuff down through a small hole you make down through what looks like the biggest molehill, in order to reach the tunnel beneath. Jeyes Fluid perhaps, or bleach - or drop a mothball or two down there.
get a toy windmill & push the stick down through one of the molehills. Apparently they don't like the noise/vibration it makes.
if you can't get a windmill, get a large plastic bottle, cut the bottom off it & then stick the bottle upside down & down through the molehill. The sound of the wind passing over the top of it makes a noise they don't like. Old CDs tied loosely to a stick work too - any noise the disc makes as it hits the stick must be the reason, I suppose.
apart from having to rake/spread the soil back over the surface, a problem arises when the tunnels themselves finally subside & this makes a lawn surface uneven.
one good thing, however, is that you probably have good soil - with plenty of worms!
