Cut out a huge butterfly from wallpaper. Cut lots of scrap coloured paper (trimmings, painted, wrapping paper etc.) into little bits and place in bowls.
Give children glue sticks and get them to work as a team to cover the butterfly and cover it with coloured pieces working as a team.
They can make caterpillars with circles of green and red paper glued on leaf-shaped paper too. Then make holes where the caterpillar has eaten with a hole punch.