What does this burrow belong to and who has been digging holes in our garden?

Hello

We have found this burrow in the garden. Does anyone know what creature might live inside it?

We haven't seen it, so it might be that it is only coming out at night. It digs tiny shallow holes all around the garden which are seemingly random. And it has left no poo or anything else around the garden which could give clues as to its identity.

Could this be some kind of bird?

Can anyone help us solve the mystery?

Thanks!