Snakes use fangs—specialized hollow or grooved teeth—to deliver venom.
Venomous snakes produce venom in glands near the back of the head. Ducts connect those glands to specialized teeth in the upper jaw, allowing venom to enter a bite wound when the snake strikes or clamps down. The term “fangs” covers several different tooth designs rather than one universal shape.
Vipers have long, hinged, hollow fangs that fold against the roof of the mouth and swing forward during a bite. Elapid snakes such as cobras and coral snakes have shorter, fixed hollow fangs. Some rear-fanged snakes, including the boomslang, have teeth with an open groove that channels venom rather than a completely enclosed tube.
Fangs are not the same as tusks, molars, or incisors. Also, “venomous” is the more accurate term for snakes that inject toxins; “poisonous” generally describes toxins that harm an animal when eaten, inhaled, or absorbed.