Keep your pet hydrated while you’re away with a self-watering bowl made from an empty 2-liter soda bottle. Use short bolts to attach a 1×2 to the side of a pet bowl. Next, screw a stout wire to the bowl, forming a circle large enough to hold the bottle. Fill the bowl and bottle with water, and then invert the bottle through the wire. As your pet drinks from the bowl, water will automatically drain from the bottle into the bowl.