I'm here to eat,
For I like your feet.
I'll annoy you now,
I'll annoy you later.
Try to fight my behinds,
and it'll get greater.
I'm often abused.
All I want to do is eat.
But your clapping and slapping,
makes a defeat.
I have no intention of annoying you.
It's just my feast,
And I'm only taking the least!

Who am I?