Southern black racer (scientific name: "Coluber constrictor"), the racer is more likely to suffocate or crush its victim into the ground, rather than coiling around it in typical constrictor fashion. Man remains the greatest enemy of black racers. Many are killed on highways and others are intentionally killed out of fear. The white chin causes some people to kill this snake, believing that it is a cottonmouth – a venomous snake more commonly called a water moccasin. The venomous snake has a white lining inside of its mouth. Racers are nonvenomous and do not breed with cottonmouths. Natural enemies include such birds of
Venomous snake of snake which are actually poisonous. "Rhabdophis" keelback snakes are both venomous and poisonous - their poisons are stored in nuchal glands and are acquired by sequestering toxins from poisonous toads the snakes eat. Similarly, certain garter snakes from Oregon can retain toxins in their livers from ingesting rough-skinned newts. , mostly on rodents, is a common indicator of snakes' toxicity with a smaller resultant value indicating a higher level of toxicity. There have been numerous studies on snake venom with a variability of potency estimates. There are four methods in which the LD50 test is conducted, which are injections