No, generally they exist where there's rotting wood, so the compost they're in might have woody bits in it. If the flowers are being eaten, its more likely earwigs or snails.

My petunias are being eaten by slugs. I've caught them at it.

I haev always loved woodlice. I used to go hunting as a child in my Nan & Grandad's garden. Used to find hundreds.

I have about a hundred living behind a garden storage box I have. They live between the wall and the plastic box.

I use the lid to pot up on, so compost and plant material fall behind.