Leaky Water Science Prank

Prank your friends and family with your very own leaky bottle set-up. Offer this harmless looking bottle of water to a thirsty friend and watch his reaction as he unscrews the cap! Water will squirt out of the holes, as if throwing him a welcome party (hehe!). To stop the spray of water, simply tighten the cap.

What you need

Push pin

Plastic bottle


and maybe a tray to contain the leaky water

Step by Step

1) Poke holes around the lower half of the plastic bottle using the push pin

2) Fill the bottle with water. 

3) Screw the cap back on tightly.


What's happening? The empty plastic bottle is not actually empty. The bottle is filled with air! When you pour water into the bottle, the molecules of air rush out to the top. 

When the cap is on the plastic bottle, air will not be able to get into the bottle to push on the surface of the water. When uncapped, air sneaks in through the top of the bottle and pushes down on the water (with some help from gravity) and the water squirts through the holes in the bottle.

Watch the video for this extension activity on our Instagram Page here! Subscribe to the Water Box and discover 10 hands-on STEM activities exploring the Water theme.