Gecko (takkhak) a type of wall lizard (Gekko gecko), also known as Tucktoo, of the family Gekkonidae, order Lacertilia. The upperpart of the body is grey, bluish grey or violet-grey; it is profusely spotted all over with brick-red and whitish grey spots. The whitish spots on the back are arranged in 7 or 8 narrow transverse series or coalesced as bands and are always more distinct in young than adults. The head is rather large and snout obtusely pointed. The head is covered with small polygonal scales. Eyes are large and it has slit-like pupils. The tail is slightly depressed.

The Gecko's call is remarkably loud and clear and can be heard from a long distance; its popular name is derived from its call. Each call consists of a preliminary cackle, then the sound tuk-kaa repeated deliberately and distinctly several times. The Gecko feeds chiefly on insects, mice, house lizards, small birds, and snakes. Its hatchling is about 10 cm long, brightly coloured, reddish brown above with white spots on the bodies below greyish brown. About 600 species are distributed worldwide. [Md. Anwarul Islam]