Ice cubes float on water because they are lighter. These little boats might not last long in a hot day but they will keep a preschooler occupied for longer than you might imagine.
: Freezing time plus a few minutes to assemble
: Under 5's
Place sticky tape across the top of a plastic cup so that it will support a straw standing up.
Part fill the cup with water and add a straw.
Place in the freezer until the water has turned to ice.
Gently ease out the ice with the straw frozen in from the cup.
Cut a sail shape from coloured paper.
Punch two holes and thread through the straw.
Fill a bowl with water to float your boats in and let the fun times begin.