What is it about cats that sets the Internet aflame?

Whether it's smart cats, talented cats, sneaky cats, surprised cats, or so cuddly you could just squeeze them cats, some of the most watched videos on Youtube feature funny felines - we're talking upwards of 10 million views per video.

ABC News' Dan Harris recently participated in an viral video experiment with a cat named George on behalf of one of Dan's favorite charities, the ASPCA. Working with Mekanism, an advertising agency that has created numerous successful viral campaigns, Dan and George starred in the Matrix-like "Hovercat" public service announcement video, which has exploded in popularity in less than a week.

Watch it here:

But what makes an online video go viral? Click HERE to read Dan's story.

In the meantime, in no particular order, here are 10 famous felines that have become Internet sensations all on their own:

1. Nora the Piano Cat: Practice Makes Purr-fect

2. Tetherball Cats

3. Talking Cat

4. Iggy the iPad Cat

5. Hidden Kitten

6. Stalking Cat

7. The OMG Cat

8. Standing Cat

9. Surprised Kitty

10. Cats Playing Patty-Cake

BONUS: 'I Love Cats' Woman in eHarmony Video Bio