New study on India's four most medically important snakes—the spectacled cobra, Russell's viper, common krait, and saw-scaled viper—has revealed that a snake's age, or life stage, is the dominant factor determining the amount of venom it produces.

Data from a centre treating snakebite victims in Jodhpur, Rajasthan, show that many patients bitten by the saw-scaled viper weren't responding well to the standard Indian polyvalent antivenom.