Some species of geckos can regrow their tail when it falls or breaks off through a process called autotomy. The tail breaks off at a specific point at the base of the tail when the gecko is threatened or the tail is pulled on. The tail will twitch on its own while separate from the body in order to distract predators while the gecko gets away. Not all geckos who lose their tails can regrow them, but the species that do regrow their tails experience different stages of tail regrowth.
When a gecko loses its tail, the tail either falls off, is pulled off or is thrown off depending on the situation. The gecko may also eat its own tail. After the tail is dropped, the gecko will be left with a small, open wound where its tail was. The gecko should be moved to a clean cage with paper towel lining the bottom so there is no chance of dirt or debris clinging to the wound.
After the gecko's tail falls off, the leftover stump begins to heal. This healing takes only a few hours. During the next few weeks, the gecko should be provided with plenty of food and supplements to give it enough nutrients to grow a new tail.
The gecko's new tail will begin to grow within a few weeks and may take a few months to a year to grow back completely. However, the new tail will not be as long or thick as the gecko's original tail, which is why it's possible to determine whether a gecko has its original tail or not.
Gecko species that can regrow or regenerate their tail, such as the gargoyle gecko, can only regrow it if the tail breaks off at a set point at the base of the tail. Even when intact, this point looks like a line. The gecko cannot regrow a tail if the tail does not break off at this point. For example, if a predator bites off the tip of a gecko's tail, it will not regrow the tip but the tip will heal over. If a predator bites the gecko's tail and the gecko drops the entire tail, it will grow back eventually.