Title:

Slither

Author:

Stephen S. Hall

Category:

Non-fiction

Rating:

Date Reviewed:

February 4, 2026

am not a fan of snakes. I couldn't imagine keeping one as a pet; especially not one of the venomous ones described in Slither. But snakes are fascinating creatures, as long they don't get too close to me. In Slither, Hall describes an experiment where researchers placed a rubber snake by the side of a road and then watched as twenty out of twenty-one drivers swerved to deliberately run the snake over. I am like that 21st driver - I won't kill them, but I also don't want them near me.

Snakes are ancient creatures; they have been around for millions of years. While having no limbs seems like an enormous disadvantage, it actually helps in certain environments, such as places with dense vegetation where the serpent can push off of the close-standing stems while gliding quickly through the flora. Snakes have adapted to many environments - deserts, jungles, forests, salt water, prairies - pretty much everywhere but the coldest regions. They possess a number of unique features, which Hall details in each chapter.

All snakes are venomous, even garter snakes. It just that some snakes don't bite, and other snakes lack the fangs and muscles to drive venom into their prey. But of the snakes that use poison, some are extremely dangerous. Although only six Americans on average die each year from snake bite (you are more likely to perish from a lightning strike or bee stings), in Africa and South Asia the toll is much worse. It is thought that India suffers 60,000 fatalities a year from snake bites. Anti-venom is expensive, requires refrigeration, and each type of snake has a different set of proteins, enzymes and toxins in its venom. Even the same species of snake can have different cocktail of poisons in its venom depending on its geographic location and the adaptations of the prey it hunts. Once sentence in the book stood out : "In the not a matter of if but when world of people who handle venomous snakes on a routine basis..." Yeah, you're going get bit. Too many people the Hall interviews in this book have disfigurations due to past bites.

The chapter on digestion was quite interesting. Snakes can go months without a meal, and then they swallow one enormous lump of prey. This sudden switch from almost no metabolism to a gigantic surge in digestion has led to a lot of research into how do they do it. During the fallow times, the stomach doesn't produce acid, the intestines wither to just a thin thread. But when prey is swallowed, insulin levels skyrocket, the digestive organs are seemingly rebuilt on the fly.

Snake reproduction chapter wasn't as interesting. Many animals have what humans consider weird shaped penises. However, the description of the giant ball of mating garter snakes in Manitoba piqued my curiosity so I looked it up on Youtube. It must be amazing to see in real life.

Limbless snakes propel themselves across the landscape with four different forms of locomotion: lateral undulation, rectilinear belly rippling (heaviest snakes), concertina (accordion-like contractions), and sidewinding. So far, researchers have not been able to replicate how sidewinding snakes crawl up dunes of loose sand. The topic is important because humans would like to build snake robots that can search collapsed mines or unstable buildings.

Snakes are thought to have poor eyesight, and no eardrums but have exquisite sense of smell (their forked tongues pick up molecules from the environment and then the tip of the tongue places those molecules into sensitive receptors.) Pit vipers and constrictors also have cells that are highly tuned to heat. Intriguely, the nerves from the pit sensor and the nerves from their eyes both map to the same part of the brain; perhaps these snakes see in thermal wavelengths.

The chapter on Burmese pythons invading Florida is disturbing. This invasive species is decimating all the native mammals, birds, amphibians and reptiles. While studying these pythons, researchers put ten of them (each was 8 to 10 feet long) in a 8'x10' room filled with natural habitat grass, weeds, branches, etc. As an experiment, they ask 19 volunteers to spend half an hour each in the room counting how many pythons could they detect. Half of the 19 searchers were expert snake hunters, yet only two of the 19 searchers found even one snake. That's how incredibly good the pythons are at camouflage. There have been multiple instances where biologists with radio tracking devices on snakes have been literally standing on the radio-tagged python without realizing it. If we cannot see the snakes, we cannot count them, so all we know is that the problem is bad and that the snakes are migrating northward.

At the end, Hall tells us that places where snakes once were common are now devoid of snakes. Habitat loss is destroying the numbers of snakes (and all other wild creatures) around the world. It seems every non-fiction book I read lately describes the dire trajectory we are on as our biosphere collapses. Our descendants will be facing unimaginable environmental and climate challenges.

This is a worthwhile read, even if you (like me) prefer to never encounter a snake in the wild.