Popular fb post says Don't throw out those used tea bags. Here is some thing you can do with them:
To keep bugs and rodents out of your house, you can place tea bags in cupboards and pantries. Peppermint tea works especially well because most bugs and mice dislike the smell.
Another says:
Hang a few used tea bags in your pantry and inside kitchen cabinets. Sprinkle the tea bags with peppermint oil to help ward off nasty pests and insects that may be lurking in your kitchen. You can also use the peppermint tea bags to keep mice and rats away.