Everyone has heard the phrase "crying crocodile tears". It means that the person doing the crying is expressing insincere remorse - either their sadness is not genuine, or they're simply using the tears to gain sympathy where none is deserved. Is this just a fanciful phrase, based upon the ironical concept that a crocodile could cry, or do crocodiles actually cry crocodile tears?
Well yes, as you can see from the photograph on the , crocodiles do produce crocodile tears! These tears are quite real and, like our own tears, are products of the lachrymal glands. These glands produce a proteinaceous fluid which is secreted behind the nictitating membrane (third eyelid, easily visible in the photograph). The fluid helps to clean the eye, lubricate the passage of the nictitating membrane across the eye's surface, and probably also helps to reduce bacterial growth. Tears are normally only noticeable if the crocodile has been out of the water for a long time and the eyes begin to dry out - which is the case in this photograph where an abnormally large amount of fluid can be seen. The alligator eye (below) shows a normal eye in which only enough fluid has been produced to lubricate the eye, so that no excess fluid is visible.
, crocodiles do produce crocodile tears! These tears are quite real and, like our own tears, are products of the lachrymal glands. These glands produce a proteinaceous fluid which is secreted behind the nictitating membrane (third eyelid, easily visible in the photograph). The fluid helps to clean the eye, lubricate the passage of the nictitating membrane across the eye's surface, and probably also helps to reduce bacterial growth. Tears are normally only noticeable if the crocodile has been out of the water for a long time and the eyes begin to dry out - which is the case in this photograph where an abnormally large amount of fluid can be seen. The alligator eye (below) shows a normal eye in which only enough fluid has been produced to lubricate the eye, so that no excess fluid is visible. 
