Today we talk about an amazing animal and an expression it has given us . First , why are they amazing ? Well , crocodiles are experts at survival . Scientists say they first appeared 200 million years ago and have outlived the dinosaurs by some 65 million years . One reason they are such good survivors is that they can go for a very long time without eating . And they are expert hunters ! They use their strong jaws to bite their prey and then they swallow their food whole . Here's another fun fact about crocodiles : When they lose a tooth they grow one right back . A crocodile can go through 8,000 teeth in one lifetime ! Okay , while these facts are fascinating , they really do not help to explain today's expression : crocodile tears . Simply put , “crocodile tears ” are fake sadness . You pretend to cry and feel badly for something when in fact … you could not care less . A great word to describe crocodile tears is insincere . But don't take my word for it . Let's hear country-western singer Dale Watson sing his song “Crocodile Tears .” But why do tears from an ancient , unfeeling reptile mean false sadness ? Well , the expression “crocodile tears ” comes from an old myth that crocodiles would shed tears while eating their prey . Another myth about crocodile tears suggests the animals are very crafty indeed . Crocodiles , the story goes , would cry tears as a false show of guilt or grief to trick their prey . The prey would come closer and then become dinner . Of course , we know now that these stories are not true . Scientists explain that crocodiles DO create tears . The fluid helps to clean its eyes . But crocodiles do not cry . Crying is purely emotional and is reserved for us humans . So , that is the origin of the phrase “crocodile tears .” Now , let's talk about how and when to use it . This is a common expression and we use it in any situation . So , I could say it to my best friend as easily as I could to colleagues at work . But , please note . You do not have to have actual tears flowing down your face to have “crocodile tears .” If you fake sadness or regret by using only words , others can still accuse you of having “crocodile tears .” One last note about this expression : Sometimes , crocodile tears are worse than insincere . Sometimes they are also hypocritical . Those are the times you are showing sadness but actually in your heart , you are quite happy about the situation .