This term Year 6 have been learning simple programming by using scratch http://scratch.mit.edu/
Scratch is a programming language that makes it easy to create your own interactive stories, animations, games, music, and art -- and share your creations on the web.
As young people create and share Scratch projects, they learn important mathematical and computational ideas, while also learning to think creatively, reason systematically, and work collaboratively.
From: About Scratch
The children were first given a 'stimulus' of fishes in an aquarium and then were advised that they would be 'emulating' this environment using Scratch.