And they come with adhesives.

Ordered this for my niece and helped my sister put them up for her. She waited all day and come sunset, only her planets (purchased separately) were glow in the dark. She's only four so it wasn't too much of a disappointment but my sister felt a bit ripped off. They do look good during the day just don't expect them to be seen in the dark at all.

These are definitely not the brightest shining stars on the ceiling but they look great and with sparkles in them they're so much fun to have above a girl's bed.