Vermin

When I arrive I'm part of a flock.
Swooping down for scraps of food.
Soaring high to that big ol' clock.
You let children chase me,
and call me vermin RUDE!

That's all I am to you, right?
Yet like you I have my kin.
We fly together to a glorious height.
Past Big ben we go,
But where you're concerned I'll never win!

Do you know who I am yet?
You should, I annoy you daily.
Stealing food or using as a toilet Sorry.
I'm not four legged and fluffy.
I'm not slimy or scaly!

Have you guessed it?
Need more time?
I'll sit and wait for Big Ben to chime.