The exact number of snake species is not known, as new species are still being discovered and described by scientists. As of 2021, there are over 3,900 known species of snakes worldwide, belonging to the suborder Serpentes. These species are classified into around 20 families, which differ in their physical characteristics, behavior, and geographic distribution. Snakes can be found on every continent except Antarctica, and they occupy a wide variety of habitats, from deserts and forests to oceans and rivers.