" The fire's lit, but the cauldron's empty, " as Ivor Dillonsby put it to me, or, in Enid Smeek's slightly earthier phrase, " She's nutty as squirrel poo."
Another example would be trees and squirrels, separately trees can reproduce by their nuts falling to the ground, please refrain from commenting about this unless there's a really strong wind they won't spread very quickly.
Our next story now takes us to Berkeley microbiology lab where we're given a 10 out of 10 to a furry squirrel who learned how to ring a bell to get a treat.