 The tortoise signals it is ready by rising up and extending its neck and legs, enabling the birds to reach otherwise inaccessible spots on the tortoise's body such as the neck, rear legs, cloacal opening, and skin between plastron and carapace.Some tortoises have been observed to exploit this mutualistic relationship to consume birds seeking to groom them.After rising and extending its limbs, the bird may go beneath the tortoise to investigate, whereupon suddenly the tortoise withdraws its limbs to drop flat and kill the bird.