A lot of different animals, like wasps, spiders, snakes, jellyfish, and scorpions, make venom. Animals like the cone snail, the blue-ringed octopus, and centipedes do, too.
Venom is a mixture of different proteins that can be very toxic to animals. While humans don’t make venom, they do carry around proteins. Proteins called keratin are the building blocks of your hair and nails. The red protein hemoglobin in your blood helps deliver oxygen around your body.
![Mark Margres.](https://wpcdn.web.wsu.edu/wp-cas/uploads/sites/648/2018/10/margres_mark.jpg)
Venom tries to disrupt the systems in our body that help keep us alive, said my friend Mark Margres. He was a post-doctoral researcher in biological sciences at Washington State University and now works at Clemson University.
In his work as a scientist, he’s also studied the venomous eastern diamondback rattlesnake. It is the largest of the 32 species in the rattlesnake family. It’s about four or five feet long. Snake venom is one of the kinds of venom scientists know the most about. Margres has collected thousands of samples of rattlesnake venom and he said proteins in the venom can do different things.