Venom vs Constriction

Venom

Venom is modified saliva produced in specialised glands and delivered through fangs. It is a complex cocktail of proteins and enzymes.

Broadly, venoms may act on the nervous system (neurotoxic), blood and clotting (haemotoxic), or tissues (cytotoxic); many venoms combine effects.

'Venomous' means the toxin is injected; 'poisonous' means it harms you when eaten or touched. Snakes are venomous, not poisonous (with rare exceptions like Rhabdophis keelbacks that store toad toxins).

Fang types

Front-fanged elapids (cobras, mambas, coral snakes) have fixed hollow fangs.

Vipers have long hinged fangs that fold back against the roof of the mouth.

Some rear-fanged colubrids have grooved teeth at the back of the mouth.

Constriction

Constrictors such as boas, pythons, and kingsnakes coil around prey and tighten each time it exhales. Research shows prey mostly dies from stopped blood flow (circulatory arrest), not slow suffocation or crushed bones.

Neither

Many snakes simply grab and swallow prey alive, such as garter snakes and water snakes eating fish and frogs, or egg-eating snakes swallowing eggs whole.