But they have differences, too. Pythons have one more bone in their head than boas do and some additional teeth, and pythons are found in the Old World (Africa, Asia, Australia) while boas live in both the Old World and the New World (North, Central, and South America). One of the biggest differences is that pythons lay eggs while boas give birth to live young, although some sand boas and the Round Island boa of Mauritius lay eggs.