How to prank your roommate's toothpaste

Do your roommates constantly steal your toothpaste? Give them a surprise - by filling the tube halfway with toothpaste (you can add food coloring to make the evidence more clear), some baking soda and vinegar in a small ziplock bag, when they try to use it the next time, the contents will be blown out onto their hands! Use this as inspiration for one of your April Fools Day pranks!