Ella - Oh look mum, I found a slater! (See: http://www.ento.csiro.au/education/allies/isopoda.html)
Me - Hm, I've never been fond of slaters.
Ella - Oh mum, can I keep him as a pet?
Me - Sure, if you promise you'll look after him.
So we put him in a take-away container and she added some grass and twigs. She'll check him now and then - gives the container a bit of a shake to seperate him from the grass.
And today she asked me to look on the internet to find out what they eat: decaying vegetable matter. Sweeeet! She's now adding some of the veggies from our fridge that are past their use by date to his habitat.