### 1 puff adders are olfactorily invisible > During one experiment, researchers from South Africa's Witwatersrand University noticed the puff adders they were tracking went undetected by dogs and tame mongooses, which would walk right over the snakes without spotting them. To test the idea that puff adders can't be sniffed out, the team trained dogs and meerkats to recognise and then match specific scents from an olfactory buffet. The animals had little problem picking out the smells of five other snake species (and even freshly shed puff adder skins), but live puff adders totally stumped these sharp-nosed detectives (check out this video for more). Clearly, even porcupines will parade right across puff adders without a backward glance.- [[Meet 4 Animals Who Use Chemical Deception to Camouflage Their Smell#1 puff adders are olfactorily invisible|View in Vault]]