Bullsnakes are sometimes mistaken for rattlesnakes and killed. Owing to its coloration, dorsal pattern, and semi-keeled scalation, the bullsnake superficially resembles the western diamondback rattler, which is also common within the same range. The bullsnake capitalizes on this similarity by performing an impressive rattlesnake impression when threatened. First, it hisses, or forcibly exhales through a glottis or extension of the windpipe. The end of the glottis is covered by a piece of cartilage known as the epiglottis which flaps back and forth when air is exhaled from the right lung producing a convincing rattling sound. It also adopts a rattlesnake-like "S-curve" body posture as though about to strike. It will commonly vibrate its tail rapidly in brush or leaves, and flatten its head to resemble the characteristic triangular shape of the rattlesnake. These defensive behaviors are meant to scare away threats, however, and not to sound an attack.
