Mystery Holes at Wedge Wood

I was at Wedge Wood to take down the tent. It had been in  situ for about a year but as it was leaking, I wished to repair it and then build a wooden camping platform before returning it. Upon lifting the groundsheet, I found numerous little holes in the ground. My first thought was that mice or voles had been responsible, but there were no tunnels and none of the holes were lined with grass.
I then saw a hole at the very edge of the tent base and this one still had its occupant, a toad. I reckon that something like forty toads had hibernated beneath my tent; for some reason, only one of them had failed to emerge from its winter shelter. The photographs show some of the holes and the toad.