Writing with Carrots? Why Not? dip it in veggie dip onto black papper. Or a banana (dipped in pudding? (I haven't figured out how to use A's fav: Seaweed . Large letters though. lots of space for these fun ideas!
I was given a group task at uni to creat a science display on the topic of pushes and pulls. As I am specialising in early years we had to aim it at the ages of years olds. We chose to use the story of The Enormous Turnip as a stimulus.