Crocodile Tears: Not Emotion, But Salt Gland Secretion for Osmoregulation

The phrase "crocodile tears" suggests hypocritical sorrow, but the biological reality is far more practical. Crocodiles don't cry from emotion—the fluid visible around their eyes comes from specialized salt glands, not tear ducts.

Physiology: Why They "Cry"

• Marine and estuarine reptiles ingest large amounts of salt through seawater and prey.
• Salt glands (lingual or orbital) secrete a hyperosmotic sodium chloride solution—far saltier than blood plasma.
• On land, this secretion overflows the eye margins, creating the appearance of tears.

Function: Osmoregulation, Not Lubrication

• These glands maintain blood salinity by excreting excess salt.
• They are distinct from lacrimal glands, which lubricate the eye surface.

Origin of the Idiom

Ancient myths claimed crocodiles wept while devouring prey—a symbol of false remorse. Shakespeare cemented the metaphor in Othello ("O crocodile tears!"), and it has persisted as a shorthand for insincere grief.

Other Animals with Salt Glands

• Seabirds (albatross, penguins): nasal salt glands.
• Sea turtles: orbital glands.
• Marine iguanas: nasal glands.

Next time you see a "crying" crocodile, remember: it's just doing its kidneys' job through its eyes.