How close is too close?

How close is too close?  This little fella doesn't seem to mind my desire to be close to it.  

 He seems content, curled up, front paw tucked into his fur.  Inquisitive look on his face.  I think he found me as interesting as I found him.  As I circle around the tree we both seem to be keeping our eyes on each other.

 I really like nature from a distance so being this close to a wild animal is a little scary I think being this close to a human might be scary for him too.

  But....I had to push the limits....

 And I did.  The cute little squirrel was no longer cute or seemed little it's cute little paw was no longer tucked into it's fur it's claws were out.  I had taken one step too close with the big, black, flashy item covering my face and he was over it.  He hissed and spat at me and I ran.  See the camera shake in the photo? 

 This big ferocious animal showed me and now I know how close is too close.