Shiver me timbers!

[skinnyblue]

Whatis happening, scientifically, when you get a shiver dowm your back, its abit orgasmic and it makes you jump? My friend practically screams, my grandma says "its someone walking over your grave" (???) and i've been told also its 'when you feel a spirit near'. But what actually is happening in your body? Thank you!

[crazy chick]

It could just be a muscle spasm or nerve twitch I don't really know