Spanish explorers in Florida in the 1700s sent word home of 'terrible lizards' - up to six metres long - which were so abundant and tightly packed in some rivers that the more adventurous could consider walking across their backs from bank to bank. There is no record of anyone having performed this feat and it would be impossible today as there are just not enough alligators (which is what these 'terrible lizards' were) left. They were slaughtered in their millions, mostly for their skins, until protection came in the 1940s. The American alligator (Alligator mississippiensis) seldom grows larger than 4m long but that is enough to make it a dangerous adversary and occasional mankiller. It is found in the swamps and rivers along the coastal plain from Virginia and North Carolina down through Florida and west to the Rio Grande in Texas. Its range seems to be spreading thanks to the increasing number of cattle water holes which it frequents. 'Gators are a big tourist attraction and can be seen sunning themselves on riverbanks beside busy highways.