The majority of snakes have solid fangs, used for piercing the skin of their chosen prey. The latest research has discovered that many of these fangs have a longitudinal groove. When the snake sinks its fangs into its prey, the venom flows down these grooves and into the bite wound.

How is it that the venom doesn’t constantly dribble out these grooves but only flows when needed? It seems the consistency plays an important role and this is where snakes have another clever adaptation. You know how tomato sauce appears stuck in the bottle then suddenly comes out in a rush? Tomato sauce is a non-Newtonian fluid, just like snake venom, which means its viscosity changes depending on how fast it’s flowing.

Snake venom turns from a viscous consistency to slightly more liquid as the fangs make contact with the skin. This allows for venom to instantaneously flow down the fang grooves into the wound. Without the attractant of the skin being pierced, the venom remains ‘sticky’ inside the snake until needed.

It is the speed of their reflexes that makes snakes such successful predators. Not only their striking speed, but also the speed at which their viscous venom turns into a more liquid form, able to flow down their grooved fangs and into the target.  

Venomous vs poisonous – what’s the difference?
Both venom and poison could kill you … the difference lies in how they are delivered to the victim. Poison is absorbed or ingested; a poisonous creature can deliver its toxic substance only if another animal touches or eats it. In contrast, venom is always injected into the victim. A venomous animal has a mechanism of some sort to inject the venom into its prey or attacker – for example fangs, spines or a sting.

Source:

Bruce Young, Florian Herzog, Paul Friedel, Sebastian Rammensee, Andreas Bausch, J. van Hemmen. Tears of Venom: Hydrodynamics of Reptilian Envenomation. Physical Review Letters, 2011; 106 (19) DOI: 10.1103/PhysRevLett.106.198103 Viewed online: [http://www.sciencedaily.com¬ /releases/2011/05/110516121728.htm]