These friendly boos are made from 100% polyester glow in the dark yarn. They appear white in daylight but have a spooky green glow when the lights go out! To get the best glow, please “charge” your boo in natural, full spectrum, fluorescent, or black light. While we strive to make our products as safe as possible, these boos are novelty items and are not suitable for rough play. Due to their small parts should not be left unsupervised with humans that like to explore the world with their mouths.