Feigning Sleep Technique

Gaara uses this technique to force himself to fall asleep. This causes him to surrender control to Shukaku, who is sealed within him. While it is the dominant personality, Shukaku has complete access to its large chakra reserves, which it uses according to its inherently destructive tendencies. Before using this technique, Gaara creates a full replica of Shukaku out of sand for it to use. Gaara emerges from the replica's forehead in order to perform this technique, where his body remains even after he's asleep. This represents a vulnerability, as opponents can focus their attacks on Gaara with the goal of rousing him. If they do successfully wake Gaara, Shukaku's personality will be suppressed again.

Trivia

 * This technique also translates to something akin to "Tanuki Sleep Technique", or in some dubs "Playing Possum Jutsu". This is a reference to Shukaku being a tanuki.
 * In Naruto: Ultimate Ninja Storm, Naruto uses a similar technique while in a pyjama costume, causing him to fall asleep while his health bar recovers.