Did you know tea is the second-most popular beverage in the world, right behind water? If you love tea and wonder what you can do with old tea bags, give this tip a try. Place 20 or so used tea bags in a bucket or watering can, and fill it with cold water. Let it steep for a few hours. Remove the bags and toss them into the compost bin. Now use the weak tea on your plants -- in the house or garden -- to feed, water and protect them. The natural antioxidants in tea will help fight fungal infection on plants and in the soil, and the scent of tea deters garden pests like mice, too.