Jellyfish larvae can get trapped in bathing suits and sting the skin.
The creatures pack a powerful sting that can be excruciatingly painful to humans, and in very rare cases, may cause death.
Study says the finding of an "intermittent anus" may shed light on the evolution of our own.
Sea lice are not actually lice; they are the larvae of jellyfish and sea anemones.
Summer winds left the Catalan shoreline covered in thousands of blue jellyfish-like animals.