Do mice climb up walls?
You're not going to like my answer,but here it is. Mice are
very,very light in weight,and are voracious eaters,and as we've
seen go to the bathroom anywhere & everywhere. Mice step in
their own fecies and urine,which is extreemly sticky,and for a
short period are able to go up or down verticle surfaces,then the
mouse eats anouther spider,bug or corn flake,relieves him[or
her]self,steps in it & the process begins anew.