fill the water to the very top of the bottle and put the lid on TIGHT. Squeeze the bottle and play with your new diving squid friend! He's even awesom...
This is the EASIEST and one of the oldest science experiments out there, I chose to glam it up a bit for my toddler to play with, and to potentially learn how buoyancy works, so far it's just fun to make him dive and surface, and I have to admit, I've played with this as much, if not more than she has, my husband even wanted to make one so he could play with one too!
Step 1: Go to the fishing section
Get a fishing lure squid, bonus! Most of them glow in the dark, they are really easy to find!