World Snake Day gives zoos and wildlife educators a chance to introduce people to some remarkable reptiles. A rattlesnake, for example, can detect warmth using heat-sensitive pits between its eyes and nostrils.
Its rattle is made of interlocking segments of keratin. A new segment forms when the snake sheds, but segments can break off and snakes can shed several times in a year. For a quick photo challenge, see if you can find the heat-sensing pit without mistaking it for a nostril.
About the observance
https://www.lpzoo.org/event/world-snake-day/
More about the featured species
https://www.nationalzoo.si.edu/animals/news/do-snakes-have-ears-and-other-sensational-serpent-questions