We have woodmice, they disappear under the decking and we find nests in the cluttered garage. I had a shock once when I lifted the lid on the compost bin to find them nested in it. They are able to climb the metal pole from which we hang the fat blocks, even the squirrel can't do that!
When I sit outside the shed in the summer, I daren't move my feet because bees constantly come and go underneath the decking. Very relaxing watching bees going about their business and not minding me. I spent ages cutting up bamboo sticks to make bee boxes and in 2 years, I've not had a single bee in them. They obviously prefer the decking, since we have rather a lot of decking (I got rid of the lawn and had it decked and paved) I find that we have more wildlife in the garden than we had previously. I have tried to plant all the things bee like, and that way I don't feel so guilty when I plant things I like. I can't survive the summer without my french marigolds!
I love the wildlife wall. I don't have anywhere suitable for one, but I pile up all my twiggy cuttings at the back of the garden behind shrubs and I know there are lots of things living there.