After laying their eggs in the burrow of an aardvark, female Southern African pythons stay around to defend them and keep them warm - not easy for a cold-blooded animal.
"Our pythons bask near to the burrow entrance until their body temperature is almost 40C - within a few degrees of lethal temperatures," says Graham Alexander of South Africa's University of the Witwatersrand.
"They then coil around the eggs to warm them."
Breeding females even turn black, in order to absorb more heat from the sun, and this care continues for weeks after the eggs have hatched.
The whole breeding cycle takes about six months, during which the females do not eat and lose 40 per cent of their body mass.
"Take take a long time to recover," says Alexander. "Some of them never do."