The infrared-sensitive facial organs of pit vipers help them detect body heat of mammal prey.
Can you find the pit organ? Hint: Look between the snake's eye and its nostril.
Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.
Chen (1990), translated in David & Tong (1997)
Daltry et al. (1997)
Gumprecht et al. (2002)
Hayes et al. (2002)
O'Connell et al. (1982)
Pough & Groves (1983)