Hi Tracie two possibilities spring to mind, one a Wren (you can see its tail usually sticking upright), and the other is a Dunnock, they can usually be seen skulking under bushes.
My Flickr photos
In reply to Alan.:
Its tail was really small and I'm pretty sure it wasn't stuck up in the air. thanks for replying
In reply to tracie c:
Here is a Wren www.flickr.com/.../album-72157629000058637
And a Dunnock www.flickr.com/.../album-72157629658787997
hummmm I'm not sure hes almost completely round maybe its a baby?
Sounds like a wren imo.
In reply to Robbo:
I also think it sounds like a Wren.
Unicum arbustum haud alit duos erithacos
(One bush does not shelter two Robins)
Zenodotus (3rd Century B.C.)