Welcome to Over50sForum! The site for people over 50 to chat, make friends, discuss, share, and generally be part of something that's fun and friendly :)
Susie we have a lot of badger setts here and I would describe them as major earth workings with a number of different exits (we also have the latrines around the fields which you get with badgers and they are not so nice )
It is difficult to work out the size from your picture but it looks very like rat hole to me.
Go careful as that looks like a fairy Dwellers (Not to be confused with a Leaflet fairy) home.They are very territorial so you are very honoured to have them in your garden