Pit Viper sunglasses fall into an interesting category ... the Army wanted to make it the host for a heads-up display unit. This thing even had an NSN (National Stock Number), meaning you can ...

a heat-sensitive pit located on the side of the head between the eye and the nostril. A pit viper uses the pit in total darkness to detect the presence of warm-blooded prey, such as mice or rats ...

Photo from Liu, Hou, Mo, Li, Li, Luo, Rao and Li (2025) Guanyinshan mountain pit vipers have “slender” bodies, reaching over 2 feet in length, the study said. Their heads are “pear shaped ...