More about the park’s burrowers.
Early spring is when our moles become active, digging up to 20 metres of tunnel a day and pushing the spoil to the surface. Here is a video, narrated by Chris Packham, about the ways in which moles are adapted to their underground life.
Southwick Country Park Nature Reserve 
Recently, for the first time, we have a mole burrowing around our garden. Often we see small circular holes at the top of mole holes and had assumed the mole had left the burrow to cross a path. However the video suggests the mole never goes above ground, so what are these holes?
Sorry I should have said at the top of mole HILLS!
There has to be a hole in the centre of the molehill for the mole to push all the soil out; if you spread the molehill out you will find that the hole leads down into the tunnels. I expect Chris Packham just means that the mole never fully comes out onto the surface; it pushes the soil out with its nose and then ducks back down.
Thanks for the information, we’re hoping it moves on soon!
Try to think of it as a lawn aerator.