Only use Gatorade or G2 bottles for the sensory bottles they are a heavier plastic so they hold up better and keep a unison look so everything looks good. They come in different sizes you can find smaller ones for small hands if you need to.
Make sure to ALWAYS seal your bottles securely! I cannot emphasize this enough. Unless you want your bottle opened and the contents poured out. SEAL IT… with glue. Duct tape can be peeled off by a determined kiddo. Glue is much harder for them to open up.
Specimen Discovery Bottle
To make a specimen discovery bottle you will need a subject. Below are pictures of a lizard and a grasshopper discovery bottle. You can really use any toy animal you can fit inside the bottle. Snakes work really well also. I usually just add water super simple. You can get fancy and incorporate a wave bottle with your specimen bottle. By adding a small amount of water with some food coloring or liquid watercolors and some baby oil or vegetable oil. I made one like this below. It is a super popular bottle though and so it is almost always shaken up. This is okay, you can play the I spy game. Or ask questions about what part of the bug do you see? Antennae, Thorax, etc…
For a list of ALL my amazing DISCOVERY BOTTLE IDEAS click the link or the image below