A water balloon with a glow stick on the inside, in a stocking, hung from trees, patio cover, or the ceiling. Same pin elsewhere said: "Put a glow ball in a white stocking and hang many from trees or the ceiling." But what are glow balls?
Glaucus atlanticus (commonly known as the sea swallow, blue angel, blue glaucus, blue dragon, blue sea slug and blue ocean slug). This little sea slug eats poisonous jellyfish and stores their venom for its personal use