The worlds shortest snakes are the thread snakes (family Leptotyphopidae). There are about 60 species, widely distributed in tropical America, Africa and parts of western Asia, and they are all shorter than 40cm (16in). The shortest of all is the very rare thread snake Leptotyphlops bilineata, which is known only from Martinique, Barbados and St. Lucia, in the Caribean. The longest known specimen measured 10.8cm (4.5in) and had such a small, matchstick thin body it could have entered the hole left in a standard pencil after removing the lead.
Some worm-like blind snakes (family Typhlopidae), which are widely distributed in the warmer parts of the world, are also very small. Typhlops fornasinii of east Africa, T. caecatus and T. hallowelli of West Africa, and T. anchietae of Angola all measure 12.7-15.2cm (5-6in). Most blind snakes (there are 150 species in all) feed on small invertebrates, especially ants and termites.
The shortest of the 'giant' snakes (the boas and pythons - all of which kill their prey by constriction) is the dwarf boa Tropidophis pardalis, found in Cuba, which has a length of about 30cm (12in). It feeds mainly on lizards, but probably takes small mammals and frogs when the opportunity arises.