Hognose

"Puff adder" is the accepted common name of Bitis arietans, an unrelated, dangerously venomous African species of viper, which incidentally does not flatten its neck in any threat display.

If this threat display fails to deter a would-be predator, Heterodon species often roll onto their backs and play dead, going so far as to emit a foul musk and fecal matter from their cloaca (in liquid form) and let their tongues hang out of their mouths, sometimes accompanied by small droplets of blood.

Heterodon platirhinos is also commonly found, but their dietary requirements can be a challenge for some keepers, and there is anecdotal evidence to suggest that feeding them a diet of exclusively rodents contributes to liver problems and a shortened life span.

[4] Leioheterodon species are imported regularly from Madagascar, but they are not often bred in captivity and get much larger, so they can pose a set of different challenges for care.

Lystrophis species are fairly new to the commercial reptile trade, and are now commonly bred in captivity, but can be some of the more expensive hognose snakes available.

[5] Although they produce a mildly toxic saliva from low-pressure secretions of the oral Duvernoy's gland, they lack a specialized delivery system required for the medical classification as venom.

[6] Compared to hollowed fangs present in viperid and elapid snakes, the teeth of the hognose are smooth and strong without grooves.

[citation needed] The role of the duvernoy's gland secretions in hunting and feeding or other biological purposes are not fully resolved.