Like many coral snakes, M. lemniscatus is nocturnal and terrestrial, digging in loose soil or litter.

[3] Breeding of M. lemniscatus is oviparous, having a clutch size of possibly 20 eggs.

[3] Alimentation of M. lemniscatus is mainly long-bodied vertebrates such as freshwater eels, gymnotiform fishes, caecilians, lizards, and snakes.

[1][3][4] M. lemniscatus is found in Argentina, northern Bolivia, Brazil, Colombia, eastern Ecuador, French Guiana, Guyana,[5] Paraguay, eastern Peru, Suriname, Trinidad, and Venezuela.

[6] Lemnitoxin, a potent myotoxic PLA2 type toxin, isolated from the venom of M. lemniscatus induces local and systemic myotoxicity after intramuscular and intravenous injection in mice, which is antigenically related to Micrurus nigrocinctus nigroxin, Notechis scutatus notexin, mulgotoxin of Pseudechis australis and textilotoxin of Pseudonaja textilis.