Based on a study by Danielle Drabeck of the University of Minnesota, she guessed that the honey badger had probably evolved a defense similar to that used by other venom-resistant critters like mongooses.
There is class of molecules in cobra venom called alpha-neurotoxins that paralyze the muscles used for breathing. These neurotoxins essentially targets the muscle cell’s nicotinic acetylcholine receptor (nAChR), preventing the cell from receiving the nervous system’s signals to keep working.
Drabeck figured that the receptor targeted by cobra neurotoxin had probably changed to prevent the neurotoxin from parking there. She extracted DNA from a honey badgers blood and sequenced part of the gene that contains the blueprint for making the receptor.
Drabeck discovered several mutations in that gene that tweak the receptor. It appears that resistance to the snakes venom alpha-neurotoxin has evolved at least four times among mammals. Cobra neurotoxin fits as well in the tweaked receptor and therefore it can’t paralyze the honey badger’s breathing.
Learn more by reading this Slate.com article Biology Finally Explains Why Honey Badger Don’t Care by Megan Cartwright.