Babies cry when you moo at them because the sound of a cow's moo is similar to a baby's cry, which can remind them of times when they were crying and sad. A 2017 study by Japanese scientists found that the acoustic properties of a cow's moo and a baby's cry are similar enough to make babies cry. The study concluded that almost all babies who heard a cow cry sound also cried. Babies are also sensitive to noise because they have smaller ear canals, which amplify loud sounds
