We’ve discussed these little things before – they look like little salt or sugar packets except they’re labelled DO NOT EAT, and you see them in all kinds of product packing, from shoes to electronics to beef jerky.
They’re desiccants, which is a technical term for something that absorbs moisture. Collect them in a container and you might find some future use for them, like if you drop your cell phone in water. (We recommend rice instead there, because unless you already have a collection of silica gel sitting around it’s a cheaper natural alternative to buying it.)
The Kitchn has some more ideas:
Kitchen uses for silica gel are practically endless. We have the packets stashed in our spice drawer, in containers of dried fruits and herbs, and with stored kitchen tools like cast iron pans, cookie cutters, and mason jar rings.
They also point to a Slate article suggesting nothing happens if you accidentally eat one of those packets. But we don’t recommend trying. Just remember when using the packets, it’s important to put them in an enclosed space, not an open-air environment. Otherwise they will quickly become saturated from natural humidity and be rendered useless. Just like you can’t use a sponge to suck up all the water in a bucket, you can’t expect these little packets to dry out an entire closet or room.