Pythons belong to the non-poisonous strangler snakes. They are widespread in the tropical part of the Old World, from Africa through Asia to Australia. They inhabit forests, but also open savannahs. They are massive snakes with a distinct neck and head. The largest species grow up to 10 meters in length. The behavior of females during breeding is interesting. They lay eggs, but unlike other oviparous snakes, they take care of them. They circle around and guard. They also ensure the right humidity for the eggs and even heat them up. They generate heat by twitching their muscles or get overheated in the sun. The dark python (Python bivittatus) has an internal compass that allows it to crawl home along an almost straight route, even if it finds itself at a distance of tens of kilometers from home. Pythons grow to a length of more than five meters and are among the longest reptiles in the world. These snakes are originally from South and Southeast Asia, but they have taken hold and spread widely in South Florida's Everglades National Park, where they probably got there as discarded pets.