Why does a leopard gecko shake its tail?

Leopard geckos are a species of gecko that are able to re-generate a new tail if it happens to drop its current one. When the tail grows back, it will be a little disfigured. Sometimes it may be wider in some areas, or it could be stubby. After a leopard gecko looses its "original" tail, the new one will never look the same way the original one had.