There is now a published paper on cats and the rotating snake illusion available at http://www.scirp.org/journal/PaperInformation.aspx?PaperID=48304#.U9togoaltok . The snake illusion is made by Professor Akiyoshi Kitaoka. See his homepage for more nice illusions: http://www.ritsumei.ac.jp/~akitaoka/index-e.html .
![My cat can see the rotating snake illusion! - YouTube](https://cdn-ak-scissors.b.st-hatena.com/image/square/3ea39ecaf612a2428a1b5261a4e0206ce8e301ab/height=288;version=1;width=512/https%3A%2F%2Fi.ytimg.com%2Fvi%2FCcXXQ6GCUb8%2Fhqdefault.jpg)