Most of us have been on the wrong end of an insect stinger. While it’s usually an unpleasant experience, stings are nothing personal.

Animals sting for two reasons, to defend themselves and/or to catch prey. How they do it is wildly varied, from simple to elaborate.

Take jellyfish, whose “stingers are among the most sophisticated biological equipment ever evolved,” says Juli Berwald, an oceanographer and author of Spineless: The Science of Jellyfish and the Art of Growing a Backbone. It’s probably why they have remained the same for hundreds of millions of years.

“When you are stung, you interact with half a billion years of evolution," she says by email.

Jellyfish tentacles are lined with thousands