I still have quite the collection of plastic bottles in my home and wanted to think of another activity to reuse them before sending the rest to the recycling center. Making them into bowling pins is a simple craft/game that does not take a lot of work and materials, but will teach your children to have fun with reusing materials.
You simply fill up your cleaned plastic bottles with tap water and then add any sort of substance that would easily color the water. Beet juice, carrot juice, cayenne powder, curry powder, dandelion root powder, cream of tartar or tempura paint would work fantastically to color the water.
I glued the top to each bottle but still was not feeling comfortable with knocking big bottles full of colored water over in my house so decided this will be an outside bowling activity.
You can also make some fun I Spy Bottles with your kids to reuse plastic bottles.