What is that thing

There is this thing that keeps following me.  It will move this way or that way depending on which way I move.  I usually don't notice it but once in awhile it will sorta just be there. 
I'll turn around in circles trying to get it.I'll even lay down to get it.  Once in awhile I'll catch it and bite it!! When I do that though it makes me yelp!! Oh well guess I'll just let it follow me.

See there it is..it's just laying there.

Wonder if I turn my body if I can get it???

I'll just pretend I'm asleep and see if it goes away.

I've got it held down..now let's see if I can taste it to see what it's made of.

I caught ii!!!! BUT when I tasted it if made me hurt..I don't think I want to do that again!