Plastic bags float through the air, make a fun crinkly sound and can be a serial killer.

WHAT YOU DO:

1. Grab three cups and two cardboard toilet roll tubes. The tubes will represent whales, turtles or other marine animals, so you can decorate them with textas, or coloured paper.

2. Stuff a plastic bag inside one tube.

3. Add water and food colouring to one of the cups.

4. Hold the empty tube over one of the empty cups and pour through coloured water. Repeat with the tube
containing the plastic bag and the remaining empty cup.
 
WHAT HAPPENED?
The plastic bag stopped most of the coloured water from pouring through, right? Good news if you want to keep your car boot clean from drippy groceries, but bad news for any turtle that accidentally swallows a plastic bag thinking it's a yummy jellyfish (plastic bags look a lot like jellyfish in the water and many marine animals swallow them accidentally). The plastic bag gets caught in the digestive system stopping food and water from getting to their stomachs. It can take up to a month for the animal to die of starvation. Afterwards, the body decays and the plastic bag is free to kill again.