February 23, 2012
On a recent blog post about Snakes, I received this very smart comment from one of our readers:
Dear Seymour Simon,
I read your SNAKES book and I found a mistake! Snakes are venomous, not poisonous. Venomous means to inject venom and poisonous means to touch or absorb it. I learned this at Lake Pleasant in Arizona. It was my field trip. My name is Jack R. I’m a student at Wildfire Elementary School in Phoenix, Arizona. I still love snakes and reptiles.
Thank you, Jack, for taking the time to write. You clearly learned a lot on your field trip!
In fact, I have received several letters lately because one of my old favorites, a book called POISONOUS SNAKES, has just been re-published. Since it is a book for kids and almost all kids (as well as adults) refer to snakes as ‘poisonous’ or ‘non-poisonous’, we decided to use that term in the title of the book when I wrote it years ago. These are also the words used in searches by kids. So, my intention was not to deceive anyone or use incorrect words, only to make the book easier for kids to fine, and to plainly label what the book is about if they were to look it up.
Jack is correct, though. Venom is injected by snakes and other animals, and poison is ingested (eaten), like when birds eat some kinds of butterflies. So technically, snakes are not poisonous or non-poisonous….they are either venomous or non-venomous.
Here are two examples, to help you understand the difference.
This is such a beautiful photograph of a lionfish, but you can’t always trust your eyes. This lionfish is venomous and dangerous to humans as well as other marine animals, because it uses those sharp spines to inject paralyzing venom.
A monarch butterfly, on the other hand, is poisonous because its larva eats milkweed, which contains a poisonous chemical. If a bird or other predator eats a monarch, it eats the poison. But you can touch a monarch without any danger - you’re safe as long as you don’t swallow it!
Notice that both the lionfish and the monarch have bright colors and patterns on their bodies. These are known as "warning colors," which keep predators away.
Posted by: Seymour Simon