This is an animation test. Yes, none of these lemmings people exist in real life (not even Waldo), so no one was harmed in the test. Creator Dave Fothergill vfx says,
Crowd dynamics test using Miarmy for Maya.
Shows the new servo force feature which allows struggling animation once the agent has become dynamic
Which means nothing to me, but digital animators will recognize the terms. If you are interested in the technical aspects, there’s more in the comments at vimeo. To most of us, it’s just a hilariously goofy sequence that you shouldn’t feel bad about laughing at. -via Metafilter
Update: And now there's a looping version with sound effects and music.