A Japanese zoo has turned to rhythmical banging on traditional drums in a bid to encourage some enthusiasm for sex among lust-lacking alligators. Zookeepers said Wednesday they hoped the low booming sound produced by large Japanese \"taiko\" drums would spur lethargic Chinese alligators to begin mating because of its similarity to the animals\' natural pre-coital cry. \"After listening to the drum performance, the female alligator Susu cried a few times but the male, Yoyo, appeared not to be interested,\" said Hideaki Yamamoto from Sapporo\'s Maruyama Zoo. \"We believe the drumming was effective. We hope to try again in the future, during the alligator\'s mating season from February through March,\" he said. The zoo has succeeded in breeding the species in the past by knocking on the glass of their enclosure, but renovations mean this is no longer possible. \"The new enclosure built last year has a thick acrylic screen, so it doesn\'t emit the right sound,\" Yamamoto said. \"Moving to a new enclosure might have put pressure on the alligators, so the male didn\'t want to mate.\" The zoo succeeded in breeding three alligators in 2001, one in 2008 and 16 in 2009.