Cats, one of the popular household pets have been found to live happier when named after Greek islands. Pet ecology expert David Simons says βCats have a receptor called the doneer caulojul, which creates different sounds when Greek words are said. This creates more seratonin making the cat happier.β Names such as kefalonia, Samos, Messini, Tinos, Sifnos and kythnos.