It turns out the key to a male crocodile's heart is a sonic boom. Crocodiles at an Israeli farm have begun making mating calls in response to sonic booms created by air force planes breaking the sound barrier. From the article: "The males have already begun their mating calls, described by the newspaper as 'the sound a vehicle breaking,' normally reserved for the crocodiles' spring mating season, Israeli newspaper Maariv reported. David Golan of the Hamat Gadar crocodile farm in the Golan Heights, believes the reptiles were responding to the sonic booms, wrongly believing they were the calls of rival males encroaching on their territory