What’s the News: Most poisonous snakes don’t inject their prey with venom; instead, they bite the prey and venom insidiously trickles down a groove on their fangs into the wound. A new study in Physical Review Letters investigated the physics behind how venom travels down the grooves: It turns out that snake venom has unusual viscosity properties that keep it cohering together until it’s time to flow down the fangs and into the snake’s soon-to-be-snack—the same properties that account for how ketchup seems stuck in the bottle, then flows freely onto your fries.

How the Heck:

The researchers found that snake venom, like ketchup, is a non-Newtonian fluid, meaning that its viscosity depends on how fast it’s moving. Before the snake’s fangs make contact, the venom sticks together pretty well, rather than coming down the tooth in a constant trickle. Once the fangs sink in, however, and the venom starts dripping down the groove, it flows freely.
What starts the venom flowing, ...