Turtles are reptiles belonging to the family of Testudines or Chelonii and are characterised by having a special cartilaginous or bony shell that act as a shield. Turtles can be counted amongst the oldest reptile families and are older than lizard, snake or crocodile families. Though, turtles inhabit in and around water, they do not lay their eggs underwater, but only on land. They also have exceptionally good night vision because of unusually huge amount of rod cells within their retinas. They have coloured vision with cone subtypes having sensitivities in the range from the red to ultraviolet (UV A).