The best way to tell whether a snake you have encountered is venomous or not is by paying close attention the shape of the head and eyes. Diamond shaped head with pupils that are vertical slits indicate a venomous snake. Non-venomous snakes have rounded heads, round eyeballs, and round pupils. If bitten by a NON-venomous snake, the bite will look like a horseshoe of tiny scratches. As opposed to Venomous snake bite of only one or two puncture wounds.