Self-cannibalism behavior has been documented in North American rat snakes, one captive individual twice attempted to consume itself, dying in the second attempt. Another wild rat snake individual was found having swallowed about two-thirds of its body.
Hoax or Fact:
The message come with a picture showing a Snake trying to eat itself from tail end, claiming that it is the self-cannibalism behavior documented in North American rat snakes. Although the authenticity of the picture shown is unclear, the basic claim about self-cannibalism in snakes is a fact.
The snake shown in the picture appears to be a California king snake, a nonvenomous, relatively small subspecies of the common king snake, which are generally found in the western United States and northern Mexico. The authenticity of the small king snake shown to eat itself from its tail end is unclear. The picture is popular online and is mostly used in humor sense, as many believe it is photoshopped.
Self-cannibalism, also called autocannibalism or autosarcophagy is the rare practice of eating oneself. This can happen naturally, as a choice, as a disorder, or in a crime. In animals, short tailed crickets show self-cannibalism by eating their own wings, some species of octopus eat their own tentacles in hunger and distress.
The self cannibalism behavior is documented in certain species of snakes like Rat snakes in North America. As mentioned in the message, one captive snake tried to consume itself twice and died in the second attempt. Another wild rat snake was also found to have swallowed about two-thirds of its own body. This was mentioned in 'The New Encyclopedia of Snakes' by Chris Mattison (2007).
Note that the California king snakes are cannibalistic in nature and may attempt to eat one another, which is why they are kept in single enclosures. A King snake, which is a snake-eater, when kept in a small enclosure, can sometimes lunge at its own tail, thinking its tail as another snake. One such incident happened with a pet King snake Reggie in 2009.