My eldest son built this contraption this morning. After a very long explanation I got out of him that it is in fact an ant trap. After it traps them it kills them. I have labeled the image on Flickr in case you want to know what the components are to build your own.
Beware ants, Angus is onto you… I am pleased to see that he not only has a vivid imagination but also some emerging architectural and building skills.
I am scared looking at it. Dunno what the ants think!
Rooster's Rail 