A flock of woodlice

I've been working hard in the garden this afternoon. I had a very overgrown raised flower bed that that hadn't been touched for far too long. I decided to get everything out and start again though I've kept some of my favourite plants to go back in.

A couple of the top bricks had come unstuck and had become home to this flock of woodlice. I looked up the collective noun and was surprised to find that all groups of lice are flocks!