Jellyfish live in the ocean. Groups of jellyfish are called blooms, swarms or smacks. Large blooms can have over 100,000 jellyfish. Some jellyfish are nearly invisible and others are brightly coloured. Jellyfish don't have brains.​

 

Jellyfish use their tentacles to sting other animals. Most jellyfish are harmless to humans but others like the box jellyfish can be very painful and sometimes kill you. Box jellyfish are almost see-through so they are very hard to find.