What the hell does ":3" represent?

[amp316]

TadpoleJackson said:

amp316 said:

I can se D: being used at the end of a sentence, but having Hello Kitty at the end of a sentence is ridiculous.  Anyway, I'm allergic to cats.

:3 

 

D:<

*screws in silencer*

You might want to quit it before fur goes flying.