Ok, here's a good opportunity to compare venomous and non-venomous snakes. The image on the lefthand side depicts a juvenille Terciopelo (Bothrops asper), this is a deadly venomous viper and, as you can see, the head scales are uniformly small and the head itself is distinctly arrow-shaped. The image on the righthand side is of a False Terciopelo (Xenodon rabdocephalus) a non-venomous snake, and as you can see, the scales infront and just behind the eyes are larger than the other scales on this snake's head. The head is rounder (although, many non-venomous snakes inflate their cheeks to look more viper-like). My advice to you is, respect all snakes. Never harrass them to perform. It's better to assume that a snake is venomous. And remember, even non-venomous snakes can bite, and many of these bites cause allergic reaction or infection.
